Roku streaming stick 4k

I have 3 Roku Streaming Sticks 4K. I had them connected to T-Mobile 5G Home Internet and had no problems. They all worked great. On April 7, 2024, I installed Xfinity WiFi. The Roku Streaming Sticks all connected to the WiFi and worked for a while. Now, they never maintain connectivity and have to constantly be reconnected. This even happens in the middle of a program. It just stops and I have to go through the initialization process all over again, and again. What’s up? Do I need to set up port forwarding? If so, which ports? I did notice that my Xfinity modem/router is ipv4. Should it be ipv6? Or does that not even matter? I read online that I need to make sure my 2.4ghz band is set to b,g,n. But that selection change is not available to the user.