I found the issue, it was actually a bad TP cable that was pushing down a pin in the AP that the pin got stuck and broke. The pins on the ethernet socket on the APs seems very weak tbh. Had to order...

I have a EAP673 connected via POE to the ER7212PC. They are both new and worked like a charm until today. I was about to move the EAP so I just plugged the cable and put in another one, still...