Connection failure from android bitwarden mobile app

Hi everybody,
im new in this forum and new to use vaultwarden

I install it in a zimaboard casaos container and all works fine in self hosted from bitwarden windows desktop app and all warks fine from web browser. But from android bitwarden app i dont connect it… it return a generically connection fail error.

in selfhosted with my https://… url that works from web browser

i use letsencrypt ssl certificate with nginx …

can anyone helps me or alternatively its possible to sync from selfhosted do bitwarden.com ? or viceversa. so i redundant my password and from mobile can i continue to use bitwarden.com and not self hosted ?

thanks a lot
bye
mauro

In my case the solution was this:

https://knowledgebase.geolantis.com/HOW%20TO/how-to-install-root-certificate-on-android-6-0-device/

good luck