Faced with a similar problem. Some time ago, the point TP-Link TL-WA901ND v1 was occasionally not allowed in the network: you have a signal, but fails to connect. At this point available through the wire. Restarting did not solve the problem. Then I noticed that in the connection table hung a multicast address. I remembered that just a couple of days ago for IPTV set up igmpproxy. Turned it off and on, Cthulhu! laptop connected to the network.