Banner Patterns in Shields and Capes not appearing when using custom texture packs.

I am working on a texture pack that just changes the looks of certain items and parts of the UI. When attempting to wear a cape or use banners in shields, they don't appear.

 

The texture pack does not come with a behavior pack, so it's completely vanilla, and only changes things visually. Unfortunately, by visually, I seem to have made shield banner patterns and capes turn invisible/not render properly.

 

To reproduce:

1. Create a texture pack (which you can do easily because Mojang provides the tools necessary to do so)
2. Change a few textures.
3. Port and Enable the texture pack.
4. If you knew what you were doing as much as I did, equipping capes and combining shields and banners should cause them to not render properly.

(Unfortunately I cannot find a solution elsewhere and this is the only place I thought to present as an issue, I am sorry ahead of time if this does not fit the general use of this forum.)

 

Update: I was told to add the texture pack to the ticket, but because it exceeds the 10 MB file limit, I've put it into a google drive folder: https://drive.google.com/drive/folders/1j-9eTlSF49LlDKbOMxWQZPUyPzyrsS0U?usp=drive_link

 

Update 2: Link should be public.