Built a Tiamat transport and it won’t move.
Can load it with troops but it simply will not move, the option just does not appear.
If I could destroy it I’d replace it with a Manticore and could at least carry on playing but there does not seem to be an option to trash a vehicle/transport.
Having a few issues on exiting combat to the geoscape, a few freezes of the game (3 so far today) so best advise is probably save the game just before combat ends.