I have spectrum and have tons of issues with the app since covid started. Worked fine until the end of February, now it buffers a lot, gets blurry for a while. Just a PITA to use and watch. Like you Netflix, Hulu and every other streaming service works fine except for spectrum app.
For Bills games I use an antenna. Maybe you can get one of the more powerful antennas. My brother has a similar issue and he usually watches on the yahoo sports app on his phone or streams it on his laptop to the tv.