Ok so it's not the buildings. probably server problems or something, don't know.

I had AKM on my hand and SVD in my back so I don't think it's weapon causing it. Did you guys log off in storage sheds or buildings? Me and my friend loggged off in storage shed and when we logged on next day I was naked with only the AKM in my hand.

http://steamcommunity.com/id/MetriMake/

Had the same problem. Quite frustrating, hopefully fix soon.