Issue description:

I was playing a 1.12.2 modpack called All The Mods 3. Before its latest update the Elite Smelting Factory I have been using had its buffer totally normal. When I updated it, as long as there are items in either input or output slots, it would not allow me to insert or swap items. I saw my favourite Minecraft YouTuber using the Basic Smelting Factory in the modpack Sky Factory 4 and I think he was experiencing the same thing. Though Auto-sort can partially compensate, this should be fixed.

Steps to reproduce:

1. Craft any Smelting Factory
2. Put some items in any of its slots
3. Try to put another kind of item in or swap the existing ones with other.

Version

Forge: 14.23.5.2825
Mekanism: Mekanism-1.12.2-9.6.9.367
Other relevant version:
All The Mods 3's version: v5.12.1

It would help if you can find/make a video that demonstrates exactly what the problem is - we recently changed things so that the slots won't accept incompatible items (e.g. so automation can't insert into a slot where the output is a different type and thus would get stuck waiting for output to empty)

I am pretty sure that bug got fixed with 9.7.0. The latest version is 9.7.7, so if you could confirm it still happens with that then we can look into it more.

This is indeed fixed in newer versions, so I guess I will wait for the modpack creators to update it. I'm not someone who updates mods in a modpack separately. :P

Going to go ahead and close this issue for now then.