The Now TV stick doesn’t have an aerial connection.
So to get “Freeview” it’s all about using the apps like iPlayer, iTV, All4 and My5.
These can be accessed regardless of there being an active Now TV subscription
Will put it this way, I don’t have an aerial. All the TV I get is through apps on my Sony Bravia Android TV.
Best move I ever did was ditching Sky for all streaming.
Perform a factory reset to the device. This often fixes any bugs on the system.