Interpolation problem (curves)

I’m looking to interpolate (create a variable font) using 3 masters, I started with medium and extrabold and then I created the master “light”, (it’s a draft file before starting the interpolation on the original file) someone could tell me how to get out of this situation?
Thank you!

Looks like the two instances are outside the design space. That makes them extrapolations, not interpolations.

Ok Thank you, I understand interpolations better now