From: Genoa, Republic of Genoa (occupied by Italy)
I made another quick test (see image) moving five German squads in different terrains, with TEMs ranging from +3 (stone building, Assault Move) to -2 (Open Ground, non-Assault Movement, a.k.a. suicidal charge).
I carried out a first series of tests (5 games) with 5 US 1st Line squads (FP = 6), then I replaced them with HS (FP = 3). The US units fired 50 times out of 50, firing First Fire and Final Fire (except in Open Ground Terrain, where they could only fire once).
The AI appears to be more than willing to fire in the enemy Movement Segment (as long as the target is within the normal range of the firing units), so I think the occasional failure to fire is due to some glitch: unfortunately, without a save game to analyse, I suspect solving the issue is an impossible task.
I'll start saving before every Movement Segment, in the hope of incurring in some less-than-willing AI units .
Chasing Germans in the moonlight is no mean sport