I got the TL-WPA4220 KIT. Connected it exacty as the manual said and it worked perfectly. 
 

1 week later, the receivers doesn't connect to the adapter (transmitter). 
 

tried to put them both in the same room, they connect again. 
Tried putting the receiver  back in its original position, doesn't connect! Even though it worked perfectly for a week in the same exact position. 
 

I tried resetting both the adapter and the receiver, but no luck.