Problems with Facebook and Messenger App

Since 23.01.2021 i have an Login Fail with Facebook App ( sorry for my bad english i‘m german ) since the new Update. I‘ve tryed some options like reseting Network Settings, uninstall the Apps and install it again, and so on but nothing works. Support wants to help me but the URL is also not working 😒 i don‘t want to reset my iPhone 11 ( iOS 14.4 ) but i don‘t know something else to do :( Could someone help me ?