The good news is, I don't think your losing your marbles, the bad news is, I think the mortar may be occasionally bugging out. I have found sometimes after ordering it to fire/barrage, the crew stand around and don't fire for whatever reason. Means you have to keep a pretty close eye on the unit and repeat commands occasionally.
Annoying as feck.
Yeah, sometimes they just won't barrage and they just stand around not even setting up the weapon. How can these bugs emerge out of nowhere without the devs even touching the mortars?
Yesterday I had mortars working just fine, had nearly 40 kills on it

So without bulletins they are fine. That video was hilarious
Should probably post that video on the official forums.