Problem with federation sharing - NC 13.0.4


I have one server with two instances of Nextcloud installed and working.
The names of my nextcloud are accessible from the internet, and I configured my trusted servers, a yellow square now appear next to the trusted servers.

The problem is that I cant share a file from nextcloud A to nextcloud B.
It tell me that the server is unreachable or use a self signed certificate ( I use lets encrypt)…
I don’t have anythings in my logs…

Can you guys help me ? Thanks

I’m not sure about this, but it could be that the certificate chain of your operating system is used to connect to the other setup. If it’s an older (or very stable) system, the letsencrypt root certificate is perhaps not included yet. I certainly can increase logging that it will show up in your logs.

For my theory, you can play around with curl on your command line:

curl --cert-status