Critical error in Hub while in Modem Mode

Looking at the Hub's Upstream and Downstream status tabs do you see signal levels that are out of the preferred range or many errors being logged ?

We need the Upstream as well, thanks.  Also setup a BQM to monitor the incoming circuit from VM  http://www.thinkbroadband.com/ping

What is supplying the network at the moment if the Hub is in Modem mode?  Is this device(s) working as expected?

You should not need to reboot the hub if you can copy the  TP Link Deco WAN MAC to your PC NIC then connect it the hub in place of the TP Link Deco to see if it connects fine.

This is still only part of the available info.
We have not seen the 3.0 Downstream power levels or any of the 3.1 Down or Up stats.

So 18 T3 timeout affecting all of the 3.0 upstream channels, if that does not change I'd suspect an engineer making a connection at a local street cabinet. It is quite unusual to see identical count of T3 error on all channels.

Same for the Downstream Post RS errors, if they now remain stable the issue has passed.

I have had an engineer to the house, and replaced the original hub5.
They could see no issue.

How would I go about escalating and refering to this thread?

Hub 3 replaced with a Hub 5 . . . 

This might be a clue,  if the TP Link Deco is connected to the 2.5GB/s port of the Hub 5, the TP Link Deco must have Energy Efficient Ethernet aka EEE Disabled on its WAN port for stable & reliable operation.

If this is not possible, the TP Link Deco should be connected to a 1GB/s port of the Hub 5.  

If you're seeing the error “No Ranging Response received – T3 time-out”, which is a DOCSIS error indicating your modem is struggling to communicate properly with VM’s network equipment (specifically, the CMTS). This usually means that even though the modem sends a Ranging Request, it doesn’t get a response, causing it to reset the connection. 

This error often points to issues in the physical connection typically on the upstream path. This could be caused by:

• Faulty, corroded, or loosely connected coax cables/connector
• Poor-quality or malfunctioning splitters/amplifiers
• Interference or noise upstream
• Issues outside your property, such as worn or overloaded infrastructure (taps, nodes, ports, etc)

If you report this became apparent after upgrading to a Hub5, The Hub3 uses DOCSIS 3.0 while the Hub5 runs on DOCSIS 3.1. On paper, DOCSIS 3.1 is a big upgrade. It allows more capacity and higher speeds but it’s also more sensitive to any noise or signal imperfections on the line. With DOCSIS 3.0 (Hub3), the connection tends to be more forgiving, so you could have borderline signal levels (e.g. upstream power slightly high, or downstream SNR a bit low) and still not notice many issues. With DOCSIS 3.1 (Hub5), those same borderline levels can cause daily drop-outs, packet loss, or latency spikes.

Or your TP Link Deco is sending out ARP and DHCP of your LAN from many source MAC and Docsis disconnects you till a reboot unlikely but who could say?

Test with a PC to the hub in modem mode and see if it disconnects.

Attaching screenshot of latest 

[MOD EDIT: Images removed due to containing private information]

Attach latest in full

3.0 Downstream channels

Channel    Frequency (Hz)    Power (dBmV)    SNR (dB)    Modulation    Channel ID
1    331000000    6.9    40    QAM 256    25
2    139000000    6.5    40    QAM 256    1
3    155000000    6.4    40    QAM 256    3
4    163000000    6.2    40    QAM 256    4
5    171000000    6.4    40    QAM 256    5
6    179000000    6.6    40    QAM 256    6
7    187000000    6.9    40    QAM 256    7
8    195000000    7    40    QAM 256    8
9    203000000    7    40    QAM 256    9
10    211000000    7.2    40    QAM 256    10
11    219000000    7    40    QAM 256    11
12    227000000    7.1    39    QAM 256    12
13    235000000    6.9    40    QAM 256    13
14    243000000    7.4    0    QAM 256    14
15    251000000    7.3    40    QAM 256    15
16    259000000    7    40    QAM 256    16
17    267000000    7    40    QAM 256    17
18    275000000    6.9    40    QAM 256    18
19    283000000    5.2    39    QAM 256    19
20    291000000    6.5    39    QAM 256    20
21    299000000    6.8    39    QAM 256    21
22    307000000    7    39    QAM 256    22
23    315000000    7.1    40    QAM 256    23
24    323000000    7.1    40    QAM 256    24
25    339000000    7.1    40    QAM 256    26
26    347000000    7.1    40    QAM 256    27
27    355000000    7    40    QAM 256    28
28    363000000    7.2    39    QAM 256    29
29    371000000    7.3    40    QAM 256    30
30    379000000    7.4    40    QAM 256    31
31    387000000    7.6    40    QAM 256    32

3.0 Downstream channels

Channel    Locked Status    RxMER (dB)    Pre RS Errors    Post RS Errors
1    Locked    40    100    32
2    Locked    40    3794772    2745
3    Locked    40    376978    3112
4    Locked    40    167326    4635
5    Locked    40    78818    2137
6    Locked    40    17773    1106
7    Locked    40    6299    675
8    Locked    40    4065    1146
9    Locked    40    1090    949
10    Locked    40    970    1484
11    Locked    40    447    680
12    Locked    39    737    1603
13    Locked    40    587    1250
14    Locked    0    480    1267
15    Locked    40    490    1185
16    Locked    40    458    961
17    Locked    40    523    1034
18    Locked    40    935    2130
19    Locked    39    1423    3133
20    Locked    39    492    1337
21    Locked    39    210    704
22    Locked    39    498    1484
23    Locked    40    492    1318
24    Locked    40    301    711
25    Locked    40    111650    61308
26    Locked    40    810    2158
27    Locked    40    610    1604
28    Locked    39    733    1959
29    Locked    40    596    1500
30    Locked    40    380    1089
31    Locked    40    312    1013

3.1 Downstream channels

Channel    Channel Width (MHz)    FFT Type    Number of Active Subcarriers    Modulation (Active Profile)    First Active Subcarrier (Hz)
33    94    4K    1840    QAM 4096    1108

3.1 Downstream channels

Channel ID    Locked Status    RxMER Data (dB)    PLC Power (dBmV)    Corrected errors (Active Profile)    Uncorrectable errors (Active Profile)
33    Locked    40    6.6    2538294811    82651