I loaded up 4.1.3 and sure enough, the options are there so your theory is correct, the 2.4Ghz / 5Ghz option has definitely been removed on later GO4 versions.
Nope, me neither now 
I was looking for a way to confirm that FCC mode is actually on / enabled.
As I suspect it’s not actually on…
But I had no idea how to confirm or determine if I’m in FCC or CE mode from within the app itself?!