So, I removed and then reinstalled the campaign. Tried again, using the menu, and nothing.
Then I decided to try saying it through Vouce Attack, as opposed to selecting through the comms menu.
It worked. Why only spoken works, I don’t know, but great.
Then after my third cat launch, DCS crashed.
FML.
@draconusI doublechecked all radio settings for both radios, had tried button 5 for both, and I also had zero issues with comms to anything else. Just requesting landing. Anyway, as above, it seemed to work speaking it as opposed to selecting it through a menu. God knows why. But thank you.