wow! thanks Slashee_the_Cow
I am surprised! that seems to require quite an advanced knowledge and long experience to understand these issues am I right? are you also a developer/contributor? seems to know a bit about the internals too..
Have you considered making a course for selling and creating a youtube channel sharing those specific things that nobody in youtube talks about? I think this problem that I had with this STL is one of them because I couldn't find anything around addressing this issue.
and just to know what awaits me, how did you get to know so much about cura and 3d printing? I thought I was already in between advanced and expert levels, but this answer of yours really got me surprised!