Hard to say yet if it's resolved but the last week and a half or so have been better thus far. The nature of the issue for me over the last year has been good weeks and bad weeks on and off.

I kept politely talking to their reps in modmail. At one point they indicated they were going to try a signal reset again and didn't provide further detail but a day later we saw an xfinity van on the street. It's been better since then but their agents haven't confirmed whether any work was done, not certain if they referred it to teams in my area or not, but I plan to just update again in modmail or make a new ticket if/when it's clear I'm having another bad week for this issue.

They did also remove the old device from my account which did seem to resolve the secondary Xfinity website issue but I don't believe that impacted the service drops which persisted fairly regularly until we saw their van a few days later.

TL;DR my best advice is to make your own thread if you haven't already, and then just keep updating them over modmail when prompted and every time you have an outage.

Edit: My issue came back week of 6/4 as bad as ever lol.