So I’ve found in the furnace (and probably other similar options) that if you pause making 1 items just before it ends, you can add entire stacks to the furnace and click unpause and it auto-completes them all.
This is also happening in live with no mods and I can get it to do it on Testlive (where I’ve got a mod active).
I sort of suspect that it’s forgotten how long it was supposed to be ‘on’ for crafting, etc. and then accepts all the new items and calculate based on being logged off or something.
I had this happen a few times, but, I have not been able to reproduce it everytime: I noticed that I got a full inventory of gruel instantly on the camp fire and it started to decay at a high rate (no issues with other benches or furnace).
Also, sometimes the fuel burns out instantly on campire, drier, and lesser wheel if they are turned on with nothing to craft.