ISU-152 Barrage not working

Hi when I try to use the barrage ability for this tank, it usually NEVER fires. However sometimes it will? (yes I make sure i have 40 muni)

This has been an issue for a while Ive just been forgetting to post this.  has this reported before?

It works for me (1.31) but theres another issue:

The ISU Main Gun does not fire an artillery projectile, it only points to the target location and then the arty shells fall down. It does not use a higher arc to fire.

The model should be changed in a way that the main gun actually fires a shell, and that it points into the sky while doing so (like the Hummel for example).

ISU can only fire (barrage) on flat ground. This problem also affects Calliopes and Hummels.