I said use the same account type: the murena account-type, not nextcloud.
That is what will make the in-built davx fork fetch all the caldav / carddav things. The nextcloud account type is reserved for the official Nextcloud client app that will not do caldav (calendar) and carddav (addressbook). I’d even just remove it. In-built eDrive will use the murena account type to do webdav. Think of your own nextcloud as your murena.io account and use the docs accordingly.
Will look roundabout like this screenshot just with your custom domain instead of murena.io.
