PlayStation 5 Internet Connection Issues

Since 1/15/22, I've been having an impossible time getting connected to the internet using my PlayStation 5. The PS5 internet connection test fails at various and inconsistent points in the process, but it never tests without issues. The device is connected via Ethernet cable. Sometimes, it fails at PSN sign-in, other times it fails at NAT Type, other times still it fails at Internet Connection or even upload speed. I've spoken with 7 reps who blamed it on an outage twice, changed from my own equipment to the Xfinity router and had a tech that replaced my lines and gave me a line directly to the pole, but I'm still having issues. I even factory reset the PS5. Using the Xfinity router, I've forwarded ports recommended by Playstation for the PS5 and placed the PS5 in the DMZ, which made no difference. I've been dealing with this for a week. I know it has to do with Xfinity, because when I create a hotspot from my phone (T-Mobile), the console's internet test results are excellent, like they used to be with Xfinity. I use internet for two things - work laptop and entertainment system PS5. It's like I'm not receiving half of the service I'm paying for. You may say you don't throttle, but in reality it seems to be a different story. Please help me.