Hey After holding it for 2-3 seconds there should be a flashing light, this indicates it searching for a WPS connection

Have you any details on the sensors themselves? Post a link to the model or manual if you can

@Dogukan20 It does sound like a fault in that specific laptop, I would say a surge protected is unlikely to make any difference but worth a try. My gut feeling however is that its a faulty NIC port...

Is it one specific laptop that causes this or any device at all? It could well be an issue with the laptop itself and you may be better getting a USB network adaptor for the laptop. I would try...

@Andreav Hey the WPS button on the WA850RE is in the middle of the blue LED circle (pic below) just press here You may find you need to press WPS on both the main AP and the Repeater first, then on...

@Riley37262 Hey That seems a rather strange behavior, have you tried changing the channel on the main router incase this is interference from another neighboring AP? Something like WiFi Analyser on...