misbehaving STL

thingiverse

I can import() the file “afraid.stl” into OpenSCAD and it will display when Preview’d. I took the same file and broke it into “parts” using PrusaSlicer, deleted one of the parts, and saved the result as “afraid1.stl” I then import() that file and it doesn’t display when Preview’d. I can render the model and save it as “Untitled.stl”. This file displays properly in PrusaSlicer but if I attempt to “import()” it into OpenSCAD, nothing displays when Preview’d.