Session/authentication issues -- users get stuck in login loops, cannot log in, or are kicked out. Clearing cookies temporarily fixes it.

The root fix for v1.18.2 session issues is to revert the class.ostsession.php patch: https://github.com/osTicket/osTicket/pull/6766/commits/416b548bd812188fec62c89fe8bfb0a3128731a1 (remove lines added in green, restore lines removed in red). After patching: restart webserver and PHP-FPM, TRUNCATE the ost_session table, clear all browser cache/cookies/sessions. Upgrade to v1.18.3 which reverts this patch in core. Additionally: disable 'Bind Agent Session to IP' (Admin Panel > Settings > Agents) and ensure TRUSTED_PROXIES is set in ost-config.php if behind a proxy/load balancer.