Plugging Into ETH1 Powers Off Router

Hello,

I have a MikroTik RB3011UiAS-RM router. It immediately powers off when I plug an ethernet cable from my SB8200 modem into the port marked ETH1 POE IN. It does not do this when plugged into any other port on the router. I have tried multiple cables, all unshielded cat6a cables. It was working fine until a recent lightning storm. I suspect I broke something because I do not know what I am doing. I would appreciate any assistance figuring out what I broke and what I need to replace/repair.

Thank you

Well, I got a replacement modem and switched my WAN port to ETH2. I think a power surge broke my modem and ETH1. Either way the new modem is on a surge protector now…