@Clive_A Thanks for helping me. All APs are EAP610 and EAP225 and no mesh. All are wired to switch.

@Clive_A I don't understand why a loop occurs in network I have only 3 switches and only use 1 LAN Cable each switch for the uplink. Switch 2 & 3 uplink to Switch 1 Switch 1 - TP-Link SG2210P Switch...

I have SG2210P v5.20 switch and 3 Ports keeps on blocking. Anybody who could help me fix my network problem?

@Hank21 There is no "device was disconnected" notice/notification for 3 Weeks. Only "device is connected" notice/notification every few minutes

@Virgo I can't find the new firmware for my hardware OC200 I have changed the POE and plugged it to UPS. Changed also the cables. Problem still exist.

@Virgo Thank you for your response. I will upgrade my controller to v5.13 and change the POE Adapter.