I'm running kolab-webadmin just tagged release 3.2.17 in Debian12 with PHP 8.2.24.
I get this in /var/log/kolab-webadmin/errors (besides lots of deprecation messages):
[27-Oct-2024 16:06:40 UTC] PHP Fatal error: Uncaught Exception: Serialization of 'LDAP\Connection' is not allowed in [no active file]:0 Stack trace: #0 {main} thrown in [no active file] on line 0
I'm running php8.2-fpm, in case that matters.