Resource Pack Icon Bug

I was making a resource pack and ran into a problem where changing icons.png would not change the corresponding images in the game. After searching for some time, I found it was a bug that occurred only in 1.20.2 and higher.

What I expected to happen was...:
Since I had made a resource pack before, I was expecting to be able to change the png and see it in game.

What actually happened was...:
It was not in the game, even though other textures were.

Steps to Reproduce:
1. Create a resource pack

2. Change icons.png

3. Boot up Minecraft

4. Use said resource pack