Hello,
Simplify3D is the only program that cannot handle possible little model errors. All other programs on the free sector have no problem and either auto-repair them or just ignore them and work. Only Simplify3D has problems with them and so holes are getting closed for one layer depending on your settings. If you rotate the model or change the layer height the problem is gone. In my eyes as software engineer (part of my profession) this is a bug but it is not accepted here as bug.
So I now start a feature request. All free programs can handle these files and a software for which I paid cannot? Sorry this is hard to understand for me as even repaired models (via online model repair service) fail to slice and should be fixed.
Kind regards,
Sven