Hi @triptheman 

Can you re-connect your ER605 to the switch? Or reboot the switch?

About the controller version, what is the controller type? Hardware OC200? Or Windows software controller. I recommend you check the recent update of the controller as we released V5.12 for the Windows software controller and V5.11 for the hardware controller.
After the update as well as the reboot, you check the connection and uplink again.

Last but not least, you should swap with a different Ethernet cable. This is very important as we have seen too many cases before as time goes by the cable degrades and eventually leads to a connection problem. Typically, it's either bad/unstable PoE or cannot negotiate. It is rare to have a bad chipset(controller) in the devices if you installed them for a long time and they worked well for a long period.