CSRF protection after connexion to another service thru NGINX

[Tos26]

Hello,

I'm looking for help on a strange behavior.

I use nginx as front-end server for several services, and directly as php server for Roundcube.
I set the HTTP basic authentication in nginx to protect all external access.

No problem for that until I install Home assistant on my server.

But now, when I'm logged on my server and connected to Home assistant, I got a CSRF protection error when I try to acces to Roundcube.

I described this issue here: https://github.com/roundcube/roundcubemail/issues/9390

I have no idea of what can I do, can someone help me ?