Problem with texture resolution when changing the texture through a dynamic material instance

I’m trying to get outlines on all kinds of different assets and the best way we found was to create an outline black and white map in Blender and use it in the material.
To reduce the number of materials I need to create, I thought I’d create a dynamic material instance and set the texture defined in the class that way.

The problem is that while it works and changes the texture, it somehow messes up the resolution of the texture and creates extremely blurry outlines.
Is there something I’m overlooking that I need to adjust to get the full resolution when using dynamic material instances?

Texture set by dynamic material instance:
image

Texture set directly in the Material:

It could be a dumb thing such as: You setting the dynamic material instance from the default material instead of the material instance which has a thicker line applied?

It could also be due to LODs or MipMaps, meaning that for different LODs the mask you are using will change depending on the distance to save on VRAM. This tutorial can be helpful to showcase how materials change based on distance using MipMaps.