Probably loop

Hello. Recently I had a power outage in the resort that i am working ( yes it is quite big ) and i noticed on mikrotik logs that i get this error :
ether4: bridge port received packet with own address as source address (74:4d:28:6a:80:20), probably loop
I have identified where ether4 leads, which is another server room with 2 switches. I have tried to unplug every single patchcord from the switches or turn them off but the issue still persists
Note that every 6-7 mins the loop happens and there is a network outage for around 5 seconds. Any solution/alternative would be very much appreciated. I am still new to mikrotik so i just use it to see the logs, nothing else. Thanks a lot!