The latest @White Noise release works well for new npubs, but if you have a lot of follows, the app connects to too many relays and gets overwhelmed, messages don't get sent or received then.
Even when you log out of that large account, the error will persist, so you'll have to wipe the storage completely and log in with a fresh of low follow count account.
Please have a bit of patience, the next release should fix that, sorry!