I believe this was an issue a couple of months ago as well, correct me if I'm wrong.
I get tuner unavailable or a blank white screen in chrome using the full player. Currently on v2022.07.29.18 through docker on unraid. No issues viewing on the NFL website.
Hoping this gets fixed before preseason spins up this week 
Thanks guys!!
Try new prerelease
I'm getting the same tuner unreachable error on the 7-31 prerelease. Thanks for the quick response
Submit diagnostics
0d22ca4a-fe33-4e58-aa50-49242962b11d
Go into Rescan menu and click rescan next to NFL, then resubmit
Cable provider authentication failed
fdbe45bc-1d6e-4040-a375-6a9977722f30
Try latest prerelease