Using a git release from around Jan 20th of kolab-plugins, connecting to radicale [AlmaLinux 9 setup, basically default], I keep getting forbidden when it tries to do a curl against /calendars.
* I also have a cyrus imapd setup, which this seems to just work
libkolab/lib/kolab_dav_client.php
* public function discover
I changed $roots to:
$roots = [
'VEVENT' => '',
'VTODO' => '',
'VCARD' => '',
];
And I see now both my calendar, as well as the addressbook showing up in calendar and tasks.
* above changed for testing, not a suggestion to fix [especially with addressbook being returned].
From that, I'd suspect the issue is that the way it is discovering the calendars is not compatible with the radicale expects.
I was comparing this to Thunderbird, which I 'think' does a propfind on / (vs /calendars) for current-user-privilege-set
* Note: I am not familiar with the specifics of the CALDAV protocol.