CM1150V Error Log De-Coding - Losing Internet Connection

I've mentioned this in couple of other threads (not initiated by me) but here is my issue correlated into a single place. 

History of my issue

CM1150V on Xfinity 600Mbps plan

Worked perfectly for almost a year - consistent full spec speeds 

Around mid Nov, began to have frequent drop-outs and occasionally throughout day but EVERY morning would have to power cycle modem to re-establish connection 

After dealing with that EVERY DAY for about 2 weeks, called out Xfinity. 

Xfinity Tech checked lines all way to street interface - no issues, installed Xfinity XB7 and all was perfect (immediate and consistent thereafter); 

Received replacement CM1150V 12 days ago and re-commissioned with Xfinity

Initially worked perfectly and consistently for 10 days then suddenly 2 days ago began having identical issues to first one 

(this makes me wonder if in both instances a firmware 'upgrade' was pushed by Xfinity?) 

Here is log from the last 12 hrs or so - note that this was while the Modem was essentially unused during the night! 

Came down to find no internet connection and this is the log showing the period of preceding 12 hrs or so 

6:44am is when I power cycled the Modem, so those errors pertain to that. 

This was the Modem Status Baseline, when the Modem was first installed about 12 days ago 

Here is a Modem Status from yesterday when it would not connect to the Internet 

Only differences I see are 

The Download Frequencies are much higher generally in the baseline 

There is a high incidence of 'correctables' in the problem status of yesterday 

Other interesting notables

When a Download has been established and continuous (such as streaming a movie) it tends to remain consistent until there is a break in download traffic 

Another way to recover the connection is just to keep requesting Speed Test - this one is curious - I can request multiple times and it fails, then it will connect with very slow download speed (only a few Mbps) and then the upload part of the test is at full spec (18Mbps); the very next speed test (run immediately after) will deliver full speed down and up. 

A modem power cycle will immediately re-establish full spec speed once reboot completes. 

The behaviour is now identical on second modem as was the original 

Both Modems were performing perfectlly & consistently before suddenly becoming consistently problematic (again this makes me suspect firmware upgrade?) 

But almost certainly rules out Hardware

The XB7 had zero issues during its 3 weeks installation (and problem was consistent with initial CM1150V prior to the XB7 install which instantly resolved it)  

What does the log indicate was going on during that night time (supposedly idle) period?