Enemy ship frozen in Z

Greetings,
When Enemy Ship is spawned there is no movement along the Z as though its ridgidbody is constrained by freeze position Z, which is Unchecked.
If I drop a prefab into the scene and hit play, it flys off down the Z, dodges, fires, tilts etc.
No errors in console and everything else works just right.
Any ides where I should be looking?
Cheers

Solution was already posted…

Space Shooter Enemy Spawn Bug