Hi @kilgore_802, thanks for posting on the forum and welcome to the SimScale Community 
@nelta’s comments are spot on from my perspective - we usually advise users not to work with STL files exactly due to the issues layed down by nelta. Since STL files are faceted, SimScale will run an operation called “automatic facet splitting”, where the platform will try to merge the little triangles which make up the model into a single surface.
Sometimes, this automatic facet splitting does not work as intended and unwanted little faces/edges remain (which seems to be the case for your analysis):
Unfortunately the solution to such an issue is not as straightforward, as this is an inherent limitation of working with STL files. The best solution would indeed be to try and remodel your CAD as a polysurface format (such as .STEP or Parasolid) using an external CAD tool (we use OnShape internally).
Cheers
Igor