There is no fix. You get it one way or the other.
1. Objects are solid. They stop things. Tanks, jeeps, bullets, shells. Everything.
2. Objects are not solid. Anything can go through them. In this case, there is no cover at all on a battlefield.
The bouncing problem is due to lack of elasticity. Everything is an entirely solid object. To compensate for that, when two objects interact, they push against each other with equal force. Problem is when you manage to shove enough of your polygons inside of something else's polygons; each one responds with equal force which builds into a massive reaction, hurling your vehicle.
I've flipped two tanks in just as many years. Don't drive into things.