Port 22001 reset

Hi Community
I’ve been meaning to get to this question for a while now. We have quite a few SNAP-PAC controllers scattered around a site and every so often a controller looses comms with PAC Display. Opening PAC terminal and trying to connect to the controller results in a Ethernet socket error (-10057) on port 22001. Then using PAC Manager on port 2001 we can read the device. Device will respond to a ping so from the outside it looks healthy.
The only way to get port 22001 active again is to restart from powerup via PAC Manager. SNMP walks show active connections but not that many to refuse connections (i think the limit is 160?).
My question is… is there a way via PAC manager or snmp? or another method to restart or release port 22001 WITHOUT restarting the controller? Has anyone had a similar problem?
Or if not, has anyone used mmp/snmp to detect non responsive ports and restart the controller?