Factorio Forums

Reproduce:
Place inserter next to a working assembler
Set output inserter to filter for the only the intended product. (otherwise it'll immediately take the item out)
Place items by hand in the inserter hand slot
Inserter will place item inside output slot of assembler, even if the inserter is in a disabled state.

Congratulations, you now have one of the dumbest ways to create a chest without a chest.

Thanks for the report. This is currently working as intended. The inserter works when it has an item in the hand regardless of what enable/disable state says. It also will put items that don't fit into the target machine into the machines trash slots rather than get stuck. These combined result in what you see.