how to file a complaint

On 5-4-25 the Xfinity Streaming app would not work on any of my 4 Rokus and would only show the "thinking" page of a gray dot with 3 blinking dots.  Any other app worked fine.  I contacted customer support and after spending 4 hours, which included rebooting my modem and router several times, 3 phone calls because the calls were dropped and 3 different technicians, I finally, while waiting for the 3rd tech to check the connections again, uninstalled the app and reinstalled it.  That seemed to work but now sometimes I still get the 3 blinking gray dots when I try to access the app.  I can only fix the problem by rebooting the app or uninstalling and reinstalling it.  And I sure don't want to call tech support and spend another 4 hours of techs checking my connections when it's the app that has a problem