Xfinity Can’t communicate with modem

Have had xfinity for 7 years. Changed modem 6 months ago. Using a nighthawk. No issues. Randomly yesterday at 11 no internet. Spent the day trying to fix it. Was able to get a decent download speed 800ish last evening but upload was 2ish. Internet went out again today similar time. Never came back. Xfinity claims they can’t communicate with my modem (ironic bc they have for the past 6 months). nothings changed on my end. Have done all the troubleshooting. In chicago, wicker park area. Live in 8 unit condo building. Others in building no issues with internet. 

Even tried my old modem, no go

cable tv is still working