My Samsung Galaxy S3 won't connect to my AT&T U-Verse router. I've gone through AT&T help and they say it's the phone. I've gone through Sprint (phone & service provider) and they say nothing is wrong with the phone. Samsung support also says nothing wrong with the phone.
It connects to unsecured networks no problem. If I turn security "off" on my U-Verse router, it connects no problem.
With security "on", I get an "authentication error occurred" error message on the phone, even though the status bar on the phone shows it sees my router at excellent strength. I have verified the password with correct upper and lower case.
I've connected to several unsecured WiFi without issue. The only secured network I have connected to is at work. I know they don't have U-Verse, but I have no idea what the WiFi brand is. It connects no problem with security on and my office password.
The phone is running Android 4.0.4.
I've changed router settings to use channel 11 and power level 400. I've rebooted the router and reset the phone.
I can also see the phone's MAC address on the router, so I know they are seeing each other.