G-code is different than the result

Hi everyone,
I am playing around with CNC systems for some years and am using LinuxCNC for ~1 year now. Today I have a problem I newer realized before:
LinuxCNC doesn't follow the g-code...
The attached image shows a screenshot with the g-code (white) and the way the machine mills the structure (red). I do not understand why the machine doesn't follow the g-code. Did I miss something? I also tried with only 25% feed without success.

The g-code looks like this:
Using
LINUXCNC - 2.8.0-pre1-5206-gb3f7b2519
gmoccapy 3.0.8.2
MESA 7i76e

Thanks for Help!
Best
JanPan

That is a common mistake of beginners in Linuxcnc.
The default setting for Linuxcnc is G64 with no blending tolerance. This causes the corner rounding you see. Set G64Pn in the preamble of your g-code files, with the n= to some acceptable tolerance.
linuxcnc.org/docs/2.6/html/gcode/gcode.html#sec:G64

Thank you!
And: Sorry for that question...
Never realized this before.

No reason to be sorry. Asking questions is one of the best ways to learn something.

I am not sure that LinuxCNC chooses the best default state really.

On some level, if you tell LinuxCNC that your axes can move this fast, and accelerate that fast, then you are really saying (just basic physics) that you understand that corners have to be rounded at high speeds.

But I doubt that many users _actually_ realise that is what they are configuring.

If LinuxCNC defaulted to exact-stop then people would be less surprised, but then the forum would be full of "Why is LinuxCNC so stupidly slow? Even my old GRBL could do better than this".