Yes, I rescanned and downloaded guide updates. I can watch all ViacomCBS channels; all but Paramount are Pacific. I manually rescanned every channel, and then did Paramount (because it errored because of location). We'll see what happens next month when channels need to re-auth their cookies.
(BTW, I'm using DirecTV credentials, but posted here because DirecTV and AT&T use the same auth backends, and the problem with Paramount matches mine exactly.)