Changing the axis default changes the interpolation

I have 2 axis, 4 master, 5 intermediate master .designspace (0,0) to (1000,1000), the default value for the weight axis was at "0" and recently I had to change it to "1000", now the intermediate masters are no longer properly part of the design space and many of the glyphs look wrong. Is there a reason why I can't set the default to the maximum value of an axis?