The Bug:
In certain circumstances, redstone dust will remain powered despise there being no power source.
This may be caused by chunk borders
How to reproduce:
Download the atteached world. There will be a complicated redstone contraption, but only a couple of block matter. On the bottom right, there is a redstone dust on lime concrete with a sign on it.
Flip the lever in front of the diamond blocks once.
Wait for the redstone to calm down
Flip the lever again, pay attention to the aforementioned redstone dust
Notice how the redstone dust stays powered despite there being no power source
Place a block next to the redstone dust
This will give the redstone dust an update, causing it to depower, but only when updated by a player
Linked issues
Attachments
Comments


Update2: Managed to isolate the bug. Check attached screenshot
Does MC-151418 describe your issue?

It might be.
Seeing as observers are involved, closing as a duplicate of MC-151418.
If you want to add more information to that ticket, feel free to do so.
UPDATE: Seems to not be related to chunk borders. The same contraption is bugging out not next to chunk borders too.