OFDM upstream not locked - any advice appreciated

Hi everyone,

I recently upgraded to the X2 plan and got a brand new Netgear CM3000 modem, which was listed as compatible here: Xfinity Compatible Devices List.

However, I'm still not seeing any improvement in my upload speeds—they're stuck at around 40 Mbps. When I checked my modem's status, I noticed that the upstream OFDM channels aren't locking.

I had an Xfinity tech come by to check the signal levels both at the street and where my modem is located. He mentioned that everything seemed fine, replaced a splitter, and even gave me a new cable between the modem and the wall outlet. He also mentioned that his manager would come by later to replace something else, but it's been a few weeks, and I haven't seen any changes.

Here's what the status page of my Netgear modem shows:

Startup Procedure
Acquire Downstream Channel: 543000000 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     28     543000000 Hz     -0.7     40.2     0     0
      2     Locked     QAM256      1     381000000 Hz     0.9     40.4     0     0
      3     Locked     QAM256      2     387000000 Hz     0.9     40.4     0     0
      4     Locked     QAM256      3     393000000 Hz     0.8     40.4     1     0
      5     Locked     QAM256      4     399000000 Hz     0.6     40.4     3     0
      6     Locked     QAM256      5     405000000 Hz     0.4     40.3     3     0
      7     Locked     QAM256      6     411000000 Hz     0.3     40.1     0     0
      8     Locked     QAM256      7     417000000 Hz     0.4     40.3     2     0
      9     Locked     QAM256      8     423000000 Hz     0.5     40.3     2     0
     10     Locked     QAM256      9     429000000 Hz     0.6     40.4     2     0
     11     Locked     QAM256     10     435000000 Hz     0.6     40.4     0     0
     12     Locked     QAM256     11     441000000 Hz     0.3     40.3     2     0
     13     Locked     QAM256     12     447000000 Hz     0.1     40.3     3     0
     14     Locked     QAM256     13     453000000 Hz     0     40.3     0     0
     15     Locked     QAM256     14     459000000 Hz     0.1     40.3     1     0
     16     Locked     QAM256     15     465000000 Hz     0.3     40.4     0     0
     17     Locked     QAM256     16     471000000 Hz     0.6     40.5     2     0
     18     Locked     QAM256     17     477000000 Hz     0.6     40.5     1     0
     19     Locked     QAM256     18     483000000 Hz     0.4     40.5     1     0
     20     Locked     QAM256     19     489000000 Hz     0     40.4     1     0
     21     Locked     QAM256     20     495000000 Hz     -0.2     40.4     1     0
     22     Locked     QAM256     21     501000000 Hz     -0.3     40.4     2     0
     23     Locked     QAM256     22     507000000 Hz     -0.1     40.4     0     0
     24     Locked     QAM256     23     513000000 Hz     0.2     40.6     1     0
     25     Locked     QAM256     24     519000000 Hz     0.3     40.6     0     0
     26     Locked     QAM256     25     525000000 Hz     0.1     40.5     0     0
     27     Locked     QAM256     26     531000000 Hz     -0.3     40.4     0     0
     28     Locked     QAM256     27     537000000 Hz     -0.6     40.3     0     0
     29     Locked     QAM256     29     549000000 Hz     -0.5     39.9     4     0
     30     Locked     QAM256     30     555000000 Hz     -0.1     39.8     0     0
     31     Locked     QAM256     31     561000000 Hz     0.3     40.3     0     0
     32     Locked     QAM256     32     567000000 Hz     0.3     40.2     1     0

Upstream Bonded Channels
Channel   LockedStatus  ChannelType ChannelID   SymbolRate        Frequency       Power     
      1       Locked       ATDMA      4       5120 Ksym/sec       35600000 Hz       43.8 dBmV
      2       Locked       ATDMA      2       5120 Ksym/sec       22800000 Hz       43.5 dBmV
      3       Locked       ATDMA      3       5120 Ksym/sec       29200000 Hz       43.8 dBmV
      4       Locked       ATDMA      1       5120 Ksym/sec       16400000 Hz       43.3 dBmV
      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 ,1 ,2 ,3     193     722000000 Hz     1.18 dBmV     40.3 dB     388 ~ 3707     551433780     448616172     17
      2     Locked     0 ,1 ,2 ,3     194     957000000 Hz     -8.12 dBmV     35.8 dB     148 ~ 3947     552852855     452535372     85249

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

Any advice or suggestions would be greatly appreciated! Thanks in advance for your help.