Minecraft 1.16.1 (Fabric)
Tom's Simple Storage 1.1.1
Stockpile 1.1.5

When you place item to the barrel via the system and then try to place anothe one to the same barrel the system freezes and start 'eating' items, witch you try to place into the system.

Reproducing:

1. Place a barrel from Stockpile mod;
2. Connect the barrel to the system;
3. Place some item to the system via terminal;
4. Try to place different item into the system.