I have found the right reason of why can’t connect to my Collabora Online server, however don’t know how to solve it.
Reason: in richdocument 3.6.0, can’t set ports to others instead of 443 ?
In my wan network, port 443 is shielded. So that I set a port forwarding rule in my router.
External port: 54321, Internal Port: 443, Protocol: tcp , Ip: Ip of my centos server
and then using the External port ( https://office.domain.name:54321 ) to vist my Collabora Online server form internet. It works fine in richdocument 3.5.3.
I just tested it in the lan network under my router. And set the “URL (and Port) of Collabora Online-server” to https://office.domain.name:443 or https://office.domain.name, then it says: Collabora Online server is reachable. However, Unreachable for https://office.domain.name:54321, and at the same time in my a nother nextcloud test server installed with richdocument 3.5.3, the https://office.domain.name:54321 still works fine.
So I think I have found this bug.
Any suggestion to solve this?
I have opened anoter Post on this issue: Can't set to other ports instead of 443 in richdocument 3.6.0?