Constant service interruptions both with cable box and Xfinity stream

As the title says, I have constant interruptions with both my upstairs TV which is plugged in to the cable box, and downstairs TV, running Xfinity stream, which is plugged in via Ethernet to the XB7 down there. I have 1000mbps internet, it says the speed to the XB7 is around 1150-1200mbps on the Xfinity app. I have literally zero problems streaming anything on my phone, nor on my downstairs TV. It’s a Samsung TV and I have the app directly installed just like all of the other streaming services. 

The XB7 is downstairs, so the WiFi upstairs isn’t ideal, but it’s usable. It’s great downstairs. What I don’t get is how that affects the cable box upstairs? It shouldn’t, right? I’ve tried switching router/modems, from an XB7 to a different XB7. No help. I’ll be getting an XB8 soon apparently and I hope that helps but I have my doubts. We’ll see though. 

So I’m hoping for any help here with both issues. Xfinity stream is often straight up unusable downstairs. I’ve tried resetting the modem, resetting the TV to factory settings, deleting and reinstalling the app, every basic troubleshooting technique possible. The fact that every streaming service works great but xfinity stream is terrible makes it clear to me it’s not a TV or internet issue. I’ve tried WiFi instead of Ethernet connection on my TV, that doesn’t seem to matter.  

I have tried similar troubleshooting on the cable box upstairs. I’ve reset it, unplugged it and plugged it back in, the cable box is also fairly new. I’ve been an Xfinity customer for decades and honestly this is unacceptable. My bill is way too high to have to deal with atrocious service on my TVs. I’ll obviously update this when I get and setup the XB8 but I don’t see how that could be the issue for both things. 

At this point, this forum is a last resort. I’ve spent countless hours on the phone and on chat with support. I’m ready to leave XFinity after 20+ years at the end of my contract in August if this isn’t fixed. My bill is absurd and the service is terrible. I had a tech out a while ago but he didn’t do much beside swap out the XB7 and give me a newer cable box. The issue wasn’t occurring at the time so we hoped it’d been fixed by the new gear, but it’s an issue that comes and goes.

Upstairs there may be a day or two where it’s totally fine, then it’ll have an interruption 5-10 times in a couple hours for about 30s-1min each. Downstairs, it’s pretty random. I’ll have a few days where it’s great, then a few days where it’s literally unwatchable. I’m talking freezing every few minutes, and often times it doesn’t even come back. It just stays frozen. 

I hope someone here can help me out. Thanks. 

-J