I'm using router that have both 2ghz and 5ghz wifi. All devices except Q80T in home connect successfully to both only Q80T can't connect to 5ghz (2ghz with same router has no problem). Distance TV to router is 3 meters (about 10 feets) and this is only router in my home so no interference.
Is this common problem?
No much of error. It just says "Connecting to wireless network was unsuccessful". I have the same password as in 2ghz network and tried it few times to make sure I put it correctly.