What is your experience level with KiCad?
I suspect you are lacking some basic knowledge of how net classes work.
You have made some extra net classes (Kudo’s for that) but have you assigned nets to those net classes?
The screenshot of your Board Setup does have a “Power” net class with a track width of 0.75mm. So it is not using the “Default” net class, which is set to 0.25mm.