I’m ower atomstack x20 and beginner.
During the test, I found that the thickness of the vertical line and horizontal line are different.
Upload photo is set constant power and line mode in LB…
Not really. This is due to the diode’s laser dot shape being rectangular rather than circular or square. In your case the dot shape is likely wider than tall. Every laser module model has a different characteristic for this with some having better conformity than others. There are variations between individual samples of the same model as well.
You could experiment with your focus to make sure it’s as sharp as it can be to see if you can reduce the effect but generally you won’t be able to avoid this.
Not sure if this is your exact laser module but found this on the Atomstack.net site: