Re: Intermittent packet loss starting in the evening.
I've been experiencing intermittent connection issues since the start of the pandemic, and having exhausted all other troubleshooting avenues, I've arrived at a hypothesis - that Comcast's backend is simply not tuned or built up to manage the additional usage posed by the number of people working from home. The commonplace is that for all the fee hikes Comcast has been levying on its users over the years, very little of it has gone back into building up its infrastructure. Some argue that Comcast sees the writing on the wall for its cable service with the advent of 5G so they aren't going to bother sinking more money into it - their future is more tied to the Peacock (NBC) than the wires.
I hope I am proven wring but I think this kind of spotty service is what we're in for for the duration fo the pandemic.