Bug Hopper stop working

[peterpunx]

Very often, the hoppers stop transfering items. Only way to make them work again is by breaking them and replacing. Bad thing, only engineers can place them.

 

[Minecraftventura]

Are the hoppers being powered by a redstone signal? In case you didn't know, (which hopefully you did) hoppers that are powered do not allow items to pass through them, this includes being placed next to a redstone block.