Model :

Hardware Version : Not Clear

Firmware Version :

ISP :

Hello. Sorry for my english, it is not the best, but writing about this things is worse!

I have a TL-WPA4220KIT. It is working fine but something curious happens. My house had a power grid designed for three phase supply. I changed the supply to monofhase and the power grid works fine with minimum adaptations. All the power grid is the same, of course, because all the plugs have electricity and I only pay one supply. But when I plug the TL to the plugs of an specific room (a bedroom) the TL is connected to the network but have no access to the internet. In the mobile device the signal is in blue color for less than one second and after that it gets grey and remain this way. The device is connected to the house network (it can interact with other devices) but can't connect to internet. If I plug it in another room's plugs, everything works fine.
What can be happening? Thanks in advance!!