Been playing the Scuba mission and Infantry mission. In both of them I've been noticing how the grass and bushes stop bullets. They seem to be block the player's and the AI's bullets.
Also the hit detection is currently awful. I can shoot 2 clips to a soldier laying on the ground 50 meters from me and he does not die.
Reload a save or start a new mission and it's there.
The bullet proof bushes have been fixed. As for hit detection, unable to reproduce in latest dev build. Since this ticket is quite old and has not seen any activity for a long time, I assume the issue has also been fixed.
However, if it is still reproducable for you, please create a new ticket and ask for this one to be re-opened.