When I have several buildings queuing units, not all buildings creates my units. For example, I had 17 stables, and several other buildings producing units.
I tried to create a horse man on each of these stables by pressing f1 and Q(multiple times) and I noticed that not all stables were producing army.
I noticed this mainly because I was not getting on 200pop.
Probably there is a limit of units queued.
A workaround will be crating building groups… But anyways, I may have lost a game due to that