Web Calendar Manager

Using external calendars cannot be working correctly!

I am using the latest /e/OS version for a long time. About a year ago I added two external calendars hosted by Nextcloud by adding a Web Calendar Manager account. Recently I moved those calendars from one Nextcloud account to another. Since then it stopped working as expected. One thing i recognized that all existing syncs or links (entries from where to sync a calendar) cannot be deleted only disabled.

First I deleted the old “Web Calendar Manager” account. The calendar was empty again. I created a new Web Calendar Manager account, I see the new entries. In the settings of the calendar app I see not only the new entries to the new calendars but also the old ones. After some time I receive a notification that not all calendars could be synced and all entries vanished, so I do everything again: delete the Web Calendar Manager account, create a new one. I do the “initial” sync and see all entries in the calendar are there twice. I go to the settings and see all entries I ever created, I disable some so that they are not syncing and are not shown. Then after some while, again I receive the notification all entries vanish and so on. Now when I sync I have each entry about ten times, as it is not possible to delete the entries.

How can this be fixed? That the phone has only one source of syncing and not all I ever entered, I went through every possible menu and was unable to find anything to delete it. I guess going through the filesystem to find the place where those are stored is not the way you want to provide to your users so how should one delete those entries?

Glad to know I’m not the only one.
I used the Web Calendar Manager to sync three calendars (ics), found that the sync did not work as expected, created another three entries, but was not able to delete the old entries (only disabling was possible).
Possibility to delete entries again should really be implemented.