Hi Pedro -
What version of LEAP are you currently running? I'm not able to reproduce this on my PC.
Based on your screenshots, it looks like you're implementing the function correctly. Note that the optional elasticity parameter defaults to 1.0, so there is no need to include it explicitly. Do you see the problem if you exclude this optional argument?
Just a suggestion: if you rename your population key assumption to exclude accented characters, does this fix the issue? If so, this would indicate a bug in LEAP.
Taylor