During the time I play DayZ I noticed zombie have some kind of X-ray eyes for sandbag buildings?
On the northwest airfield and other kind of military airfields when hiding for other players, the zombies can see you through it?
https://i.gyazo.com/315d6eab93aea202a59a2dcab31aae5b.png
This is the buildings I mean. Same issue with the sandbags near the walking paths.