Wifi constantly going out

I posted previously about this issue and thought it was resolved. The wifi goes out constantly, briefly, usually a minute or two at a time. It is incredibly disruptive to get work done, watch tv, do anything. 

We got a new modem which seemed to help for a bit but now it is once again constantly going out. The app or automated phone/assistant messaging always says our wifi looks great and there are no issues. 

I tried calling the 800 number again to attempt to talk to a human being and schedule a service appointment but got too frustrated. I'm busy and at work, not at home, so don't have time to go through all the troubleshooting that we already do every day. We restart the router almost daily. It has been months and months of frustration. I just want a person to come to our house. 

My neighbor uses Xfinity and had the same issue. She said she had a service provider come out and they found "water in a junction box" or something - once it was fixed, they have not had issues. 

I plan to drive 20 minutes to the Xfinity store today and *hopefully* can schedule a service appointment in-person since it seems impossible to do over the phone or online. Will share if we make progress. I wish we could switch providers but there are limited options in our area.