It's ok for me too, but it seems a lot of people are having the same problem since the Battlenet update. According to this thread, Blizzard are looking into it:
"Battle-net launcher - logion session expired"
https://eu.forums.blizzard.com/en/wow/t ... /449124/38"Blizzard 3h
Hey all,
As was mentioned in the post linked a bit earlier in the thread, we’re taking a look into that from our side to see what’s causing that to happen.
Thanks for the reports submitted so far, it’s always helpful to have multiple examples for our development teams to look into in situations like this!"