Just finished a game vs Ragnarok [ my host ].
Map: Spaceport, every hex = pavement....
My infantry dug in on turn one...Ragnarok wondered about this, and he was right.
Field Gunners (2xAC5) ID:1 (Klappspaten) digs in and takes cover.
Field Gunners (AC2) ID:2 (Klappspaten) digs in and takes cover.
Shouldn't be possible...
Tactical Operations, page 108:
Digging in is an option in any type of
terrain except roads, pavement, buildings and water.
...so this seems to be a bug.