SG500 changes VLAN config

[zgeorgios]

I've connected recently on an SG500X and an SG500  several devices and all of a sudden the port VLAN settings change to default, PVID1, and Tagged all available Vlans. In an instance, I connected a Yeastar PBX on an untagged vlan40 port, and all of a sudden it went back to untagged VLan1.In another instance, I've connected Sonicwaves and the port went from trunk to access port.

[marce1000]

   - Check device logs when this happens (or better use a syslog-server) , then look for clues.

 M.