Hopper Clock Duplication Glitch

If you make a simple hopper clock, after a random amount of time, the items will start duplicating.

This glitch is breaking all my hopper clocks!

It duplicates in BOTH hoppers too.

I've seen up to 10 duplicated items (after only putting one item in) in those hoppers.

It might be when you unload the chunk that the duplication occurs...

Sometimes it happens, sometimes it doesn't though.

It's really random.