@bavihai 

Hey

This sounds like an issue with your network connection or DHCP server and not anything to do with the EAP.

The EAP gets its IP address via DHCP from the Router (ISP or Omada Router) not the controller.   If its not getting an address that would indicate a cabling or network issue (DHCP SERVER OFFLINE), especially as these are LAN based connections.    The fact the controller LOST connection to the EAP also indicate a network cable issue, no cable no connection.

From what you said I would start to look at your cabling, have you ran a network tester over the cable?   How long is your cable run?

Also try the EAP via a patch cable direct to the switch (1 meter) see if it appears?  This would rule out a switching issue.

  @bavihai If I where you I'd consider do not use this model anymore or even TP-Link omada. It is unacceptable that TP-Link abandoned this model without any firmware updates.