CalDAV Synchronisation only in one direction


I have the problem, that the CalDAV Account sync only in one direction, eM Client --> Server --> Smartphone.
When I create a date in eM Client it syncs over the Server to my Smartphone.
The other direction doesn’t work, Smartphone --> Server -/-> eM Client.

According to the protocol one file was downloaded, but it is not displayed in the calendar.

I use the new Version 7.1.

and the caldav server  name ?

The Webhoster With Outlook and Blue Mail works fine.

So, the Synch-Protocol:

Problem: The @ symbol ist changed in %40  and so it comes to an BadRequest.
But one file is downloaded but can not displeyed in the Calendar.

I am also having my calendar at and experience the same problem. Is there a solution to it?
Kind regards

Ahhh. I found out. I just had to remove the CalDAV account in eM Client and recreate it where I replace @ with %40 in the CalDAV URL.