Does anyone know how to fix this issue?

I’m making a liquid inside a bottle shader. It works so far, but as you can see the top side of the geometry doesn’t render and I can’t find any way to fix it. Do you know what can I do to fix it?

https://preview.redd.it/zd7sfitw8a151.png?width=1920

Why is there a mask of the B channel? That’s probably the cause of the top (and bottom I bet) not being drawn. B = Z axis, so any rendering of the Z axis data of the material is going to not happen if masking it out without replacing it with something. What are the general properties of the material (Shading Model, Blend Mode, etc)?