I recently played a QB against the AI...I used both my off-map mortars, they had a handful of WP rounds + something else, but when they ran out of HE rounds they were completely unusable (showed as 'out of ammo' or whatever it says). After it happened on the first one, I watched the second one do the exact same thing. lists secondary ammo types, runs out of HE, goes winchester / unusable.
is this a known bug? apologies if this has been asked / answered, couldn't find anything in search.