BUDs sometimes don't act like in vanilla

[Erwann Lagouche]

Client version: 1.12.2
Server OS: Manjaro Linux
Cuberite Commit id: (Found at the top of the server's console output)

Expected behavior

BUDs work like in vanilla

Actual behavior

BUDs introduced in #2965 sometimes do not conform to vanilla behaviour. In the following example, after updating the redstone signal with the lever on the right, it is possible to update the piston not only with the blocks directly next to it, but also with the orange marked blocks, two blocks from it.

Removing and replacing the green block can also update the piston state, but I think it's Notchian.

Steps to reproduce the behavior

Reproduce the setup shown above (without the orange blocks).