Shift-clicking fuel into non-empty furnaces only moves fuel client-side

Note: May be related to MC-126363 where items cannot be added to a furnace that already contains that item.

Does this bug occur in 1.12.2 as well?

I haven't checked. Give me a sec...

No, it doesn't.

Is this happening on a world created in 1.12.2? Does this happen on all worlds?

I'm not sure, but this doesn't seem to be a duplicate to me... The other issue is caused when you use a 1.12.2 world and update it, this is any furnace regardless of when the world was created.

So you create a new world, shift-click items into a furnace (and it works), and when you close the inventory, the items move back?

That is correct. The furnace has to have something to smelt in it already, but yes exactly.

Thanks redstonehelper, that's a lot clearer 😃

Can confirm.