[Fechado] Menu problems with a privat/public buddyboss install on rapyd

Hello, I am new to WPML and did the installation/ translation today, english to German. Seems to have worked.
1. I cannot find a documentation / video for using the menu sync feature, so I failed. Please provide.
2. I set up a menu manually, logged out main menu in German with the translated links:
2.1. I set the translated links in buddyboss menu to public: Menu items are showing, but a 404 error occurs, not when logged in as Admin.
2.2 Maybe there are settings to adjust in Litespeed or other settings for caching or server. Please specify.
I can provide you admin credentials. Best, Jochen