Issues with Active Directory and Mobile Account not syncing.

A couple of my remote MacOS users with AD accounts are unable to sync their filevault and AD creds. Typically we have users log into the VPN and then change passwords locally in system preferences. In a couple of cases I have users who can’t seem to authenticate to the domain from their login screens. We have another local account on all our machines that is just a non-admin VPN access account. The current work around is to log in there, get on the VPN and switch user (which takes their AD creds). This is a temporary fix and reboots prompt the issue to return. I’ve checked and they both have Secure Token enabled. Is there a good fix for this? One of my co-workers suggested I rebind the machines to our domain but I’d like to avoid that. Happens with Catalina and Big Sur.