Caldav Task Sync: Permission Denied on Desktop

I have tried to use the following tools to manage my Disroot tasks locally on Fedora 36 via the Gnome Online Accounts Nextcloud integration. On all of the following tools writing/editing tasks fails and reading succeeds:

Despite downloading of tasks succeeds (albeit slowly), in every case, when trying to add a new tasks or editing an existing one, I always receive the following error:

Cannot create calendar object: Permission denied

I think it might also be an issue with Disroot servers being too slow, as these task managers are not asynchronous and will just time out.

Any ideas or advice?