For anyone who runs across this -- if you are re-sharing wifi, it will do it on the band you are not using. That is, if you have WiFi on, and you're connected to a 5ghz WiFi network, you can only share a hotspot via 2.4ghz. This is when using the compatibility mode that supports both 5ghz and 2.4ghz.
I am a necromancer and this may not apply to OP's ancient dead post.