i built a shop full of redstone. it works except for this bug. if i play on 1.11.4 it works flawlessly but as soon as i use 1.12.0 the items disappear. there in the chest when there on the rails and once the mine cart drops down onto the detector rail that is an a slope the mine cart gets blocked by a piston but there are no items in the chest anymore. the weird thing is though that this only happens half the time its random. half the time the items stay in the chest and the other half they just vanish