Internet continually dropping. 3 Visits to Store/ 2 comcast and one Motorola Modem tried, Tech came out?New UPS/ STILL NOT WORKING!!!

As it says in the subject line, I have been trying to resolve problems with my Xfinity Internet for months. I've visited the store (3x), replaced my modem, tried 2 Xfinity modems, bought a UPS to rule out line fluctuations. Nothing has worked. The tech who came out says he has checked everything he can check remotely and there are no obvious problems. 

MY experience is that the internet drops many times a day, sometimes just slowing down, sometimes with the gateway totally rebooting. Looking at the logs from my Motorola I can see lots of events. Not tech savvy enough to understand what is going on, but as a consumer I can confidently say that for a family with two work from home professionals who spend large parts of each day in Zoom meetings, remote recording sessions, using Adobe software that needs to stay on line,  and transferring large files, Comcast and Xfinity are worse than worthless.

Adding my voice to the many many others on this forum complaining about the same experience.

I've also found it is impossible to change the extinct email from 2012 on my forum account. I've created a new login with a good email, but when I log in with that, the old profile shows up. And yes, I cleared my cache and tried a different browser.