Issue with texel size? UV and Stencil painting

Hi all,

I have a model split into 2 different UV maps.

I was painting in stencil mode, the image textures are actually hooked up to the proper UV in the shader editor.

It seemed to work fine, but as soon as I hit something placed on the second UV the resolution of the painted image becomes a total mess.
To get it to paint right I had to sixtuple the power of 2 texture.

Now, I was trying to bake a low poly to a high poly. I’m getting an even weirder issue where the normal map produced is completely scrambled and shows gree/red patches (think a venusian Harlequin costume).

The only thing I haven’t tried yet is to save a secondary file and remove all but one UV map. Somehow I doubt that will fix anything though, as even with the prior issue I was getting the same results in a new file with a copy/pasted object.

Is anyone aware of any reason for this wierd behaviour or some mesh/edit mode specific setting I may have mistakenly applied to the base mesh?

I’m was thinking the issue is texel size related, since the 2 UVs have different densities, however sine this is happening even with 1 UV this is making much less sense.

Reviewing things, I noticed one of my textures was not power of 2, however not the texture having issues. I literally have nothing else to go on…

To update this, removing ALL other materials I was able to eventually bake correctly.
A rather weird behavior, considering none of the materials had any textures attached to any part of the Principled shader…
The stencil painting still won’t work, so they are separate issues…