My YunoHost server
Hardware: Other ARM board / …
YunoHost version: 4.1.7.4
I have access to my server : Through SSH | through the webadmin | direct access via keyboard / screen | …
Are you in a special context or did you perform some particular tweaking on your YunoHost instance ? : no
I have installed the YHN community version of Onlyoffice.
I have a main domain, for example, mydomain.com
I have created another sub domain called office.mydomain.com. This is where I have installed YNH Onlyoffice. (Yes it is secure with LetsEncrypt)
Once the app has installed, if I then go to office.mydomain.com I get the OnlyOffice welcome screen to say that the server has installed. Good.
If I use the Desktop app for Onlyoffice > Connect to cloud > Add Cloud
Select ONLYOFFICE
I use the address https://office.mydomain.com
But I get “check the cloud URL” 
What have I missed?
If I use the https://office.mydomain.com as the document server in my Nextcloud instance it works fine in Nextcloud…
I currently use Onlyoffice within Nextcloud which works ok but I’d like to get Onlyoffice out of Nextcloud so that Nextcloud isn’t working too hard!
Dj