Dropper Tower not dropping into the final chest

Hi! I was working on a dropper tower for one of my farms, and it gets stuck without dispensing in the final chest.

All the droppers are full of items, and the idea is that when someone takes an item out of the final chest, it will refill from the dropper tower. This works for the most part, as when I take an item out of the top dropper, it refills, but the final one doesn't drop into the chest. UNLESS: I mine the chest. If I mine the chest then put it back it works again OR if I don't replace the chest, it will just drop the items onto the ground.

However, after a while, it will break again and not go into the chest.

Please help me with this!

https://preview.redd.it/jpd857bsc7jh1.png?width=446&format=png&auto=webp&s=1ba35fa72a98cc1f9b3393d0d73b438f2ac82e89

https://preview.redd.it/5wbia0iwc7jh1.png?width=492&format=png&auto=webp&s=0b3f0260ea56499d0a55febc9d3ad0adc1d60993