Finally got my first 802.11ac device (MBP 2013) to work with AirPort Time Capsule. However, for some reason, 802.11ac only works in 5GHz network. Is this normal? Does it somehow depend on the ATC regional setting, and if so, which one is better? I have Australia to Vietnam version, so there is no US, UK, etc. I also have a lot of 802.11n devices in the house, if that is a factor.