Something similar is happening to me, but in mission 6. Everything is cool through takeoff, but after that the mission never advances again. I never get another message to "hawg 1-1" from the mission voiceover, even after flying through all waypoints.
Totally agree this must be frustrating. I've been stuck in the same 10 minutes of game time for weeks. First the Chinook wouldn't land (M5). Then the flight wouldn't startup (M6). Then the mouse wouldn't work (in VR), and now progression is busted.
On a positive note, this is the best campaign I've ever played. Thanks Ranger79! ;-)