Frequent intermittent connectivity issues - T3 timeouts

My internet drops multiple times throughout the day. There are times when the connectivity issues are so frequent that the internet is unusable. I WFH so this has been incredibly frustrating.

 

This issue started about a month ago.  At that time I was using an ARRIS SURFboard SB6141, which I've had for 10 years without issue. When I started experiencing connection drops, I replaced the modem with a NETGEAR CM3000.  That obviously didn't resolve the issue.

 

I've called Xfinity many times, and each time they'll say the issues are caused by the new modem and that it isn't properly provisioned.  Each time I'll mention that the issues STARTED before the new modem, and each time they'll "provision" the modem again and say that I shouldn't have issues going forward.  I still do.

 

Finally a tech was sent out to my house last week.  He looked outside and inside -- he didn't see any issues and said all signals look good.  He replaced the coax cable going to the modem.  The internet seemed fine after that, but the drops started happening again that same evening.

I am incredibly frustrated. I can tolerate a few connection drops in a day, but back-to-back drops that renders the internet unusable?  There has to be a solution to this.

 

FYI: I've had Xfinity for the last 10 years without any issues, but in the last few years new homes have been built around me.  One of those homes went up this year and I believe the Xfinity pedestal is now a part of that house's backyard. 

Here is the info I captured right after the last connection drop.

Startup Procedure
Acquire Downstream Channel:  489000000 Hz  Locked
Connectivity State:         OK                   Operational
Boot State:                     OK                   Operational
Security:                         Enabled           BPI+
IP Provisioning Mode:   Honor MDD     IPv6 only

Downstream Bonded Channels
Channel LockedStatus Modulation ChannelID  Frequency     Power    SNR   Correctables Uncorrectables     
      1      Locked     QAM256     20     489000000 Hz     7        45.5     76     262
      2      Locked     QAM256     13     447000000 Hz     7.1     45.7     83     306
      3      Locked     QAM256     14     453000000 Hz     7.2     45.8     86     306
      4      Locked     QAM256     15     459000000 Hz     7.2     45.7     95     285
      5      Locked     QAM256     16     465000000 Hz     7.1     45.7     101   281
      6      Locked     QAM256     17     471000000 Hz     7.1     45.6     89     293
      7      Locked     QAM256     18     477000000 Hz     7.2     45.6     61     299
      8      Locked     QAM256     19     483000000 Hz     7.2     45.6     83     273
      9      Locked     QAM256     21     495000000 Hz     6.8     45.4     83     251
     10     Locked     QAM256     22     501000000 Hz     6.8     45.3     79     229
     11     Locked     QAM256     23     507000000 Hz     6.7     45.3     72     246
     12     Locked     QAM256     24     513000000 Hz     6.4     45       56      251
     13     Locked     QAM256     25     519000000 Hz     6.3     45       69      247
     14     Locked     QAM256     26     525000000 Hz     6.3     45.1     84     246
     15     Locked     QAM256     27     531000000 Hz     6.4     45       87      251
     16     Locked     QAM256     28     537000000 Hz     6.2     45       77      276
     17     Locked     QAM256     29     543000000 Hz     6.2     44.9     75     234
     18     Locked     QAM256     30     549000000 Hz     6.4     45       79      259
     19     Locked     QAM256     31     555000000 Hz     6.5     45.1     66     247
     20     Locked     QAM256     32     561000000 Hz     6.3     44.9     44     236
     21     Locked     QAM256     33     567000000 Hz     6.2     44.8     60     235
     22     Locked     QAM256     34     573000000 Hz     6.3     44.9     71     206
     23     Locked     QAM256     35     579000000 Hz     6.5     45       66      192
     24     Locked     QAM256     36     585000000 Hz     6.3     44.9     57     191
     25     Locked     QAM256     37     591000000 Hz     6.3     45       58      153
     26     Locked     QAM256     38     597000000 Hz     6.6     45.1     63     116
     27     Locked     QAM256     39     603000000 Hz     6.8     45.3     57     147
     28     Locked     QAM256     40     609000000 Hz     6.7     45.1     39     160
     29     Locked     QAM256     41     615000000 Hz     6.7     45.1     53     148
     30     Locked     QAM256     42     621000000 Hz     6.9     45.2     42     125
     31     Locked     QAM256     43     627000000 Hz     7.1     45.4     47     125
     32     Locked     QAM256     44     633000000 Hz     6.9     44.8     48     130

Upstream Bonded Channels
Channel   LockedStatus  ChannelType ChannelID   SymbolRate        Frequency       Power     
      1       Locked       ATDMA     17       5120 Ksym/sec       16400000 Hz       40.5 dBmV
      2       Locked       ATDMA     18       5120 Ksym/sec       22800000 Hz       41.3 dBmV
      3       Locked       ATDMA     19       5120 Ksym/sec       29200000 Hz       41.8 dBmV
      4       Not Locked       Unknown      0       0       0       0.0
      5       Not Locked       Unknown      0       0       0       0.0
      6       Not Locked       Unknown      0       0       0       0.0
      7       Not Locked       Unknown      0       0       0       0.0
      8       Not Locked       Unknown      0       0       0       0.0

Downstream OFDM Channels
Channel   LockedStatus  ProfileID  ChannelID    Frequency       Power       SNR/MER    ActiveSubcarrier    Unerror    Correctable   Uncorrectable
      1     Locked     0 ,3 ,1 ,2     193     690000000 Hz     7.68 dBmV     44.9 dB     328 ~ 3767     74612709     23517703     5092
      2     Locked     0 ,3 ,1 ,2     194     957000000 Hz     8.18 dBmV     44.3 dB     148 ~ 3947     74535478     4271708       3273

Upstream OFDMA Channels
Channel   LockedStatus    ProfileID    ChannelID    Frequency       Power
      1     Not Locked     0      0     0 Hz     0 dBmV
      2     Not Locked     0      0     0 Hz     0 dBmV

Event Log
 Time                                     Priority           Description
Sat Nov 22 18:33:27 2025     Notice (6)       CM-STATUS message sent. Event Type Code: 8; Chan ID: 17; 
Sat Nov 22 18:33:00 2025     Warning (5)     Dynamic Range Window violation
Sat Nov 22 18:33:00 2025     Warning (5)     RNG-RSP CCAP Commanded Power Exceeds Value Corresponding to the Top of the DRW;
Sat Nov 22 18:33:00 2025     Warning (5)     Dynamic Range Window violation
Sat Nov 22 18:33:00 2025     Warning (5)     RNG-RSP CCAP Commanded Power Exceeds Value Corresponding to the Top of the DRW;
Sat Nov 22 18:32:59 2025     Notice (6)        CM-STATUS message sent. Event Type Code: 7; Chan ID: 17; 
Sat Nov 22 18:32:57 2025     Critical (3)        No Ranging Response received - T3 time-out;
Sat Nov 22 18:32:56 2025     Critical (3)        16 consecutive T3 timeouts while trying to range on upstream channel 0;
Sat Nov 22 18:32:56 2025     Critical (3)       Unicast Maintenance Ranging attempted - No response - Retries exhausted;
Sat Nov 22 18:32:56 2025     Critical (3)       Started Unicast Maintenance Ranging - No Response received - T3 time-out;
Sat Nov 22 18:31:51 2025     Critical (3)       No Ranging Response received - T3 time-out;
Sat Nov 22 18:31:32 2025     Notice (6)       DS profile assignment change. DS Chan ID: 33; Previous Profile: ; New Profile: 1 2 3.;
Sat Nov 22 18:31:31 2025     Notice (6)       DS profile assignment change. DS Chan ID: 32; Previous Profile: ; New Profile: 1 2 3.;
Sat Nov 22 18:31:30 2025     Notice (6)      TLV-11 - unrecognized OID;
Sat Nov 22 18:31:21 2025     Notice (6)      Honoring MDD; IP provisioning mode = IPv6
Sat Nov 22 18:31:18 2025     Critical (3)     No Ranging Response received - T3 time-out;
Sat Nov 22 18:31:12 2025     Critical (3)     Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;
Sat Nov 22 18:30:42 2025     Critical (3)     Started Unicast Maintenance Ranging - No Response received - T3 time-out;
Sat Nov 22 18:30:39 2025     Critical (3)     No Ranging Response received - T3 time-out;
Sat Nov 22 18:30:30 2025     Warning (5)     ToD request sent - No Response received;
Sat Nov 22 18:30:20 2025     Critical (3)        No Ranging Response received - T3 time-out;
Sat Nov 22 18:29:49 2025     Warning (5)     Dynamic Range Window violation
Sat Nov 22 18:29:49 2025     Warning (5)     RNG-RSP CCAP Commanded Power in Excess of 6 dB Below the Value Corresponding to the Top of the DRW;
Sat Nov 22 18:29:49 2025     Warning (5)     Dynamic Range Window violation
Sat Nov 22 18:29:49 2025     Warning (5)     RNG-RSP CCAP Commanded Power in Excess of 6 dB Below the Value Corresponding to the Top of the DRW;
Sat Nov 22 18:29:49 2025     Warning (5)     Dynamic Range Window violation
Sat Nov 22 18:29:49 2025     Warning (5)     RNG-RSP CCAP Commanded Power in Excess of 6 dB Below the Value Corresponding to the Top of the DRW;
Sat Nov 22 18:29:49 2025     Warning (5)     Dynamic Range Window violation
Sat Nov 22 18:29:49 2025     Warning (5)     RNG-RSP CCAP Commanded Power in Excess of 6 dB Below the Value Corresponding to the Top of the DRW;
Sat Nov 22 18:29:49 2025     Critical (3)       No Ranging Response received - T3 time-out;
Sat Nov 22 18:29:36 2025     Notice (6)      US profile assignment change. US Chan ID: 43; Previous Profile: 13; New Profile: 12 13.;
Sat Nov 22 18:29:32 2025     Notice (6)      DS profile assignment change. DS Chan ID: 33; Previous Profile: ; New Profile: 1 2 3.;
Sat Nov 22 18:29:31 2025     Notice (6)      DS profile assignment change. DS Chan ID: 32; Previous Profile: ; New Profile: 1 2 3.;
Sat Nov 22 18:29:30 2025     Notice (6)      TLV-11 - unrecognized OID;
Sat Nov 22 18:29:22 2025     Notice (6)      Honoring MDD; IP provisioning mode = IPv6
Sat Nov 22 18:29:12 2025     Critical (3)      DHCP failed - DHCP Solicit sent, No DHCP Advertise received;
Sat Nov 22 18:28:34 2025     Notice (6)      Honoring MDD; IP provisioning mode = IPv6
Sat Nov 22 18:28:15 2025     Warning (5)   ToD request sent - No Response received;
Sat Nov 22 18:28:15 2025     Critical (3)    16 consecutive T3 timeouts while trying to range on upstream channel 0;
Sat Nov 22 18:28:15 2025     Critical (3)    Unicast Maintenance Ranging attempted - No response - Retries exhausted;