Scaling Y-axis red

I have repeatedly have had the problem on the red laser where the Y-axis (height) scale is expanded. Example, if I want to vector cut a 100 X 100 box the box will be cut 100 (x) X 150 (y). I haven’t measured exactly by what factor the scaling is off (120% 130% etc), or whether this is variable. I do not know if this also occurs with rastering . I have been using Inkscape.svg files.
Any help would be greatly appreciated. I want to try fix it in Inkscape, if possible (in other words importing files to Ai would be a last resort).
Thank you so much for any help you can give!!!
Mike