MB8611 not producing Gigabit Extra speeds

Since I needed to provide this to Motorola, here is an update to the connections page: 

Connection

Startup Sequence        Startup Step Status Comment       Acquire Downstream Channel 621000000 Hz Locked       Upstream Connection OK Operational       Boot State OK Operational       Configuration File OK       Security Enabled BPI+       Connection Status        System Up Time 0 days 05h:09m:57s         Network Access Allowed         Downstream Bonded Channels         Channel Lock Status Modulation Channel ID Freq. (MHz) Pwr (dBmV) SNR (dB) Corrected Uncorrected    1 Locked QAM256 20 621.0 -1.9 40.8 38 129    2 Locked QAM256 13 579.0 -1.8 40.9 0 0    3 Locked QAM256 14 585.0 -1.6 40.9 97 460    4 Locked QAM256 15 591.0 -1.4 40.9 100 466    5 Locked QAM256 16 597.0 -1.3 41.0 129 488    6 Locked QAM256 17 603.0 -1.2 41.0 116 415    7 Locked QAM256 18 609.0 -1.4 41.0 118 491    8 Locked QAM256 19 615.0 -1.7 40.9 141 489    9 Locked QAM256 21 627.0 -2.1 40.7 110 475    10 Locked QAM256 22 633.0 -2.1 40.8 101 510    11 Locked QAM256 23 639.0 -2.1 40.9 142 494    12 Locked QAM256 24 645.0 -2.0 40.9 100 530    13 Locked QAM256 25 651.0 -1.8 40.9 143 446    14 Locked QAM256 26 657.0 -1.7 40.9 121 464    15 Locked QAM256 27 663.0 -1.6 40.9 108 467    16 Locked QAM256 28 669.0 -1.9 40.9 103 455    17 Locked QAM256 29 675.0 -2.0 39.7 125 495    18 Locked QAM256 30 681.0 -2.1 40.9 100 481    19 Locked QAM256 31 687.0 -2.2 40.8 136 472    20 Locked QAM256 32 693.0 -2.4 40.6 113 499    21 Locked QAM256 33 699.0 -2.4 40.6 102 475    22 Locked QAM256 34 705.0 -2.6 40.6 111 478    23 Locked QAM256 35 711.0 -3.0 40.5 108 482    24 Locked QAM256 36 717.0 -3.3 40.4 135 473    25 Locked QAM256 37 723.0 -3.6 40.3 133 478    26 Locked QAM256 38 729.0 -4.0 40.3 133 475    27 Locked QAM256 39 735.0 -4.6 40.2 116 493    28 Locked QAM256 40 741.0 -5.4 39.9 128 484    29 Locked QAM256 41 747.0 -5.7 39.7 15279 16774    30 Locked QAM256 42 753.0 -6.1 39.4 19933 29269    31 Locked QAM256 43 759.0 -6.4 39.3 103 486    32 Locked QAM256 44 765.0 -6.2 39.3 125 481    33 Locked OFDM PLC 193 805.0 -5.3 38.8 126917895 0    Upstream Bonded Channels         Channel Lock Status Channel Type Channel ID Symb. Rate (Ksym/sec) Freq. (MHz) Pwr (dBmV)    1 Locked SC-QAM 17 5120 35.6 45.8    2 Locked SC-QAM 18 5120 29.2 45.3    3 Locked SC-QAM 19 5120 22.8 44.8    4 Locked SC-QAM 20 5120 16.4 44.5    5 Locked SC-QAM 21 2560 40.4 48.3    6 Locked SC-QAM 22 2560 10.4 44.5

Hello everyone. For those who are following, or for those in the future who are reading, I will try and update this thread as it proceeds to its conclusion. My issue is still unresolved, so yesterday I contacted Xfinity chat support again, and they have now opened a ticket for a tier 2 technician to call me and come out. I haven't received a confirmation email or text, but I did provide the ticket number the first CSR gave me to a second CSR and that CSR confirmed that the ticket was open, it was indeed for a tier 2 technician, and that it was all in order. They said I may have to wait up to 48 hours to receive a call from them. 

Here is what the representative from Motorola was telling me. They say that the modem is functioning properly, and said that "I have noticed in the event logs you have multiple t3 time outs- which indicates network drops/packet losses that the unit has been experiencing intermittent connection. In the connection page, your downstream bonded channels pwr were in the range bn -7 to +7, snr are bn 30-50, corrected&uncorrected - are not 0 shows these channels are experiencing a signal issue, while in the upstream bonded channels the pwr levels are bn 38-50."

She also notes that the technician plugging directly into the back of the modem and getting those speeds and not the ones I am supposed to receive (even though the cables apparently check out) means that Comcast is using the incorrect speed file. 

Hello all!

As promised I am here to provide an update. The tier 2 tech did not need to call, text, email, or anything, and what he was sent to do did not require a home visit. They checked everything and it all checked out. They marked the job as complete, but I still had the same issue. Since I was not aware that they did not need to call, text, email, etc (as I was told they would need to) I was back on the chat with Xfinity to find out where the tech was which is when the CSR explained that they completed their work and did not need to do any of that because it wasn't a home visit. 

The solution, or seemingly at this time, appears to have been a bootfile for my modem. The CSR I spoke with today informed me that the wrong bootfile was being used, and they corrected it. After the bootfile was changed, my modem rebooted, and sure enough, my speeds skyrocketed. My tower uses Windows 10 64-bit, Ryzen 5 2600x, 16GB RAM, SATA-SSD (Shhh), and mobo has a gigabit port. The cable is a Cat5E, about 40 feet, and about a year old. Without changing any config on my end I am currently getting 685.22mbps down and 41mbps up directly from the modem. 

I have a mb 8611 modem, I can achieve 1400 Mbps + on a computer from 2011..