@Rossy133 

Hi,

There is nothing on the Ethernet ports of the Archer BE550 that could blink or flash. 
If you want to verify the status of the connection you have to log into the router's web management interface and check the "Ethernet Status" and the "Clients" list.

The traditional Ethernet ports that had two LEDs to indicate the link speed and whether data is being transferred have become extremely rare on routers designed for home use. 
Although, certain router models do have single status LEDs for each Ethernet port on the top or the front of their housing.