Looks like Decals in SW 2020 are completely broken. I tried to recreate this 2019 tutorial (projecting a decal onto a curved face: SOLIDWORKS - Using Decals on Irregular Surfaces - YouTube
And instead, SW2020 gives me this weird situation, where the decal has an enormous inexplicable offset because of some sort of mapping bug.
See attachment if you want to play around yourself.
I'm taking this to my VAR now. I guess it's my own fault for joining the SW2020's beta testing program (aka SP1).