I can confirm this. This is caused by =BTC=Revive and not by VAS. This happens with simple custom filled ammo box gear or pre configured loadouts for specific soldiers too. Even if you pick up lots of stuff from dead guys. It varies from losing some gear to completely emptying your backpack/vest/shirt. It seems like it has problems with properly saving the gear.
This is the only thing that keeps us from using it in our missions. Which is a shame since it would actually be great.