Crew members in open-top tanks sustained minor injuries from small-arms fire

After the recent updates, I’ve noticed that crew members in open-top tanks can now sustain minor injuries from small-arms fire.

What I mean is that when shooting at them with rifles or SMGs, you only get white hit markers. They no longer seem to be completely immune, as they were before, but at the same time, they’re not as easily killed as they used to be.

Is this a bug, or is it a new feature/mechanic?

Then being immune to small arms fire WAS the bug.