Problem caldav/carddav behind reverse proxy

Hello,
i have a nextcloud installation in a docker container on my NAS, also i have enabled a reverse roxy to access it via ssl, i’m using a custom implementation of reverse proxy available in the NAS interface (so i don’t have a lot of room there)

the issue is that i would like to connect my caldav and carddav to thunderbird (i’m using the addons tbsync with caldav/cardav provider), but when i tro to add the account i get an error, that is similar to the one that i can see in the settings of nextcloud:

  • Il tuo server web non è configurato correttamente per risolvere “/.well-known/caldav”. Ulteriori informazioni sono disponibili nella documentazione.
  • Il tuo server web non è configurato correttamente per risolvere “/.well-known/carddav”. Ulteriori informazioni sono disponibili nella documentazione.

and also i get a timeout error

i’ve found a few information here in the forum, but those works with modifiing the reverse proxy config, and i can not do that (i’ve tried for what i can but didn’t work)

any suggestion on how to fix this?

ps. i was able to connect to sync that with the davdroid app on my android phone.