Industrial Foregoing Version: 1.10.4
TeslaCoreLib Version: 1.12.2-1.0.15
Crashlog (If Any):
I made a tree farm to make charcoal to burn in the petrified fuel generator using the resource furnace. I used conveyors a black hole unit several dropping conveyor upgrades, insertion conveyor upgrade and lastly extraction conveyor upgrade.

after the furnace filled up with wood it would go to the black hole unit for storage. then I had a extraction on the black hole unit too feed wood back into the chest that was receiving the wood from the tree farm. also had extraction units pulling from the chest to the conveyor that went over the furnace where I had the dropping upgrades.

so more or less I had a loop to keep items moving over the dropping upgrades. that in turn kept the furnace full. but never used any or the wood up. but it kept making charcoal. I've had the same 12 pieces of wood going for over a hour.

tested this also on the fuel generator and the bioreactor and was able to duplicate the bug.

It appears that the dropper dose not reduce the value or the stack of items on the conveyor, and with it going in and out of a storage unit the items never de-spawn.