3D Modeled Potions are not rendered correctly in the "GUI Display"

The Bug

Specifically this issue affects the "Fluid" that these models have, not only Potions but anything that has a fluid on the inside of the 3D models.

Steps to Reproduce

1. Download and activate the following resource pack: 3D Potions.zip
2. Look at any potion in an inventory
   -> The liquid inside of the flask is rendered incorrectly
3. Look at a potion outside of the GUI, for example by throwing it on the ground.
   -> The potion is rendered correctly

Examples

-Potions

-Splash Potions

-Lingering Potions

-Honey Bottle
-Experience Bottle
-Dragon's Breath

The only models that has no problem is the Glass Bottle, since it's empty on the inside.

Like the title suggest, this rendering problem is only present in the GUI display, outside of this the models are displayed correctly.

Potion held by a Wandering Trader

Potion held by a Witch

Placed on an Item Frame & first person view

Dropped on the ground

3D Person view in both hands

Side note: the model transparency seems to have z-fightning issues as well, something that wasn't present on previous Snapshots.

Still pretty hard to tell from this Screenshot,