Shared CalDAV calendar is read-only in Roundcube, but writable in other clients

[samuelolavo]

Hi,

I'm currently using Radicale v3 as my CalDAV server and I have configured shared calendars using LDAP groups for access control.

In my setup, users who belong to a specific LDAP group (example-group) have read/write permissions to a shared calendar. Everything works fine when accessing the calendar from external clients like Thunderbird — users can create, edit, and delete events as expected.

However, when accessing the same calendar using Roundcube with the Calendar plugin ([1] https://git.kolab.org/diffusion/RPK/), the shared calendar shows up correctly, but it is read-only — users are unable to add or edit events.

From the Radicale logs, I can confirm that:

The user is authenticated via LDAP

The user has RW permissions on the collection

Roundcube successfully connects to the calendar and fetches the data

No permission errors are logged on the server side

Is there any known issue with group-based shared calendars or something else I might be missing in the plugin configuration?

Thanks in advance for your help.

Best regards,
Samuel