Summary:
In 1.18.20.25 Beta, the player's hunger bar does not deplete in the following mash-up worlds:

• Adventure Time
• Star Wars
• Steven Universe
  (The following were tested in 1.18.20.30 Preview by Auldrick)
• Ultimate City Mash-up
• Norse Mythology Mash-up
• Chinese Garden Mash-up

Other official mash-up worlds may also be affected, but I do not own them currently, so I am unable to test them.

Steps to Reproduce:

1. Download one of the mash-up packs from the list above
2. Create the mash-up world
3. Set the game mode to Survival and the difficulty to Easy, Normal, or Hard
4. Sprint jump around the world for a long time
5. Observe the hunger bar

Observed Results:
The player's hunger bar remains full the entire time.

Expected Results:
The player's hunger bar should deplete as it does in normal worlds.