Summary:
In 1.18.30.30/31, it is no longer possible to stack normal campfires. If a world from 1.18.12 is opened in 1.18.30.30/31, any stacked normal campfires remain stacked, but if you click on them, all of the campfires except for two disappear.

Steps to Reproduce:

1. Obtain two normal campfires
2. Attempt to stack them in the inventory

Observed Results:
The campfires cannot be stacked.

Expected Results:
The campfires should be stackable, just like soul campfires.

Video:
Minecraft 2022-03-29 17-07-31.mp4