I noticed quite often that when I have a tank with a stock morter in it, and I target a tower that is fairly far away, sometimes the red terget lead indicator will be in the wrong place. It looks as if it is in the appropriate place for an MDM morter. If I use the targeting point, the regular morters fall way short.
I've seen this in many of the 1.3 MPI maps.
This has been reported by a few people during testing. It may be too much work to fix, I don't know.
It seems to be only the stock mortar that's messed up. It seems to mirror or double the leader when target is over 200m away.
Simple rule of thumb for using stock mortar is if you over 200m away, you won't hit anything. The TLI works fine for 200m or under.