Registration status depends on AMI events (PeerStatus), check in the eventfilters in manager.conf if you have that disabled or not. If they are disabled you won't get updates on registration status. Also, registration status might behave strange in user & device mode in FreePBX, mostly due to the fact that user_login_out.agi script in many FreePBX versions is broken, there are posts in this forum telling you how to find out if yours is broken and how to fix it, unfortunately as that script varies from FreePBX version to version, there is no fixed file that works for everyone. If you use a recent FreePBX version then it is not an issue as it was fixed since version 12 or so.

Best regards,