I’m using plesk premium email with caldav, it’s working fine on Thunderbird and my iPhone.
On eM Client, I can do the setup, I can see it syncs the subfolders. But nothing appears on the calendar panel. Only local folders.
I think it’s an issue with eM client 8.0.2951 (e2fe9f0) installed on Windows 10 ver. 1909
Installed eM client 7.2.37929.0 and I have no issues.