Good point. I ran into that with Spectrum as well and that could be an ESPN app issue. But most of my problems with Spectrym suggest it is their incompetence…automatic authentication on their network should just work.
This has been a problem in some shape or form since the very beginning of WatchESPN. Still hasn't been fixed. Definitely frustrating. I have a Roku and it happens constantly.
I had the same issue for years. Switched browsers to Edge (just for the games), zero issues logging into my DirecTV account on ESPN+ since. So - I run 2 screens, one with Edge in full screen for the game, other with my normal chrome for normal stuff. Hope that helps.