Squiggly lines from Substance Painter to Unreal Engine 5 on texture applied to mesh?

Hello!

So,

I made a texture in Substance Painter with hand painted strokes on it, which appeared clean on the mesh in the program. However, after taking that texture and applying it to the mesh in Unreal Engine 5, those strokes in particular have gone wonk and seemed to have changed shape.

Here’s the original in Substance with the (bad, smart [Blender]) UV unwrap.

Here was what it looked like when imported to engine (don’t mind the cloth physics; they looked the same before the cloth physics in the physics asset was applied).

My initial inclination is that the issue resides with the UVs, as they were Smart Unwrapped in Blender (to variably poor result). This texture is also being applied via UDIMs, which used the 1001 or first-in-order application method to apply across all of the tiles.

This entire model really needs a makeover, but I’ve been curious about this phenomenon for present and future reference.

Any ideas on what could be going on?

Any thoughts or suggestions would be immensely appreciated!