1.5.35147 - Rounds Passing through vehicles?

[Apocalypse31]

I've had this happen on multiple occasions.

 

Last night, while playing a multiplayer session I encountered a T-80 that seemed to be invincible. I fired 3 AP rounds from my M1A2 that seemed to pass right through him with no effect. I attempted to flank him, but only got off 1 round (passed through him again) before he killed me.

 

Whats up with this issue? It's a huge turn off for Combined Arms.