Very strange layer height problem

Over the past few days, I've encountered an interesting problem that I couldn't solve and found out why.

I've been using my home printer for over a year now, with no particular problems. I recently installed slic3r on a new laptop and it worked as before. But then I realized that prusaslic3r can also be configured for non-prusa printers.

Everything worked as expected until one day I started printing and by the time I got back I found only a bunch of molten plastic that barely reminded me of the shape of the object.

I tried the same settings with a 20mm cube. The result was that I got it, one-third as high as it should have been, and of course it was shapeless because it contained as much plastic as a 20mm cube.

When the g code was generated from pc, the result is a perfect cube.

What's even weird is that I get the same bad print from both programs on my laptop.

And i can't find any difference in the g-code when i open it in txt, the layer hight is 0.3 on every z step.

My question is, can this happen because the two program is based on slic3r and somewhere in the libraries things get mixed up?

Has anyone ever had such a problem?