needs confirmation, but it sure seemed to me like zombies would only attack my wooden box, wooden frame cart’s box when it was on hard surfaces, but if I drag them AND it over dirt/grass they would happilly climb on without ever doing damage to the cart in the process/instead.
Seems like any time they are on hard surfaces they like to get a hit or two on the cart when its being used as a mobile shield.
I can’t think of any reason for this to be so unless its a bug.