In the past, this issue was resolved by applying the material belonging to the SkeletonDataAsset into the inspector (for SkeletonGraphic). However, now that URP is active... regardless of if the
SkeletonGraphicDefaultmaterial or the SPINE's actual material is selected, (in this case, it'd be
Shu_Material) the lines that are seen around the mouth area and other parts (collar) won't smoothly disappear. I believe that the lines are different "layers" that our artist prepared before animating the file, but these things should go away (they have in the past) when working in Unity (both Game and Scene views). I have already imported the URP SPINE extra shaders/etc., but I noticed that they are not to be used with SkeletonGraphics.
If you have any pointers, advice, or ideas, that would be awesome! Or if you need more information, I can post more screenshots and details. Thanks in advance!
Edit: We're using Unity 2019.4.28f1!