Trouble with overlock stitches on my sewing machine

Hmm, I need to think about this.
Do the settings in the 1st photo produce the result in the 2nd photo? You don't even have that stitch option among the ones suggested (on the top part of the machine).
In the 3rd and 4th photos, everything seems to match up, you just need to play around with the stitch length and width here.
Try experimenting on a scrap of fabric with a regular zigzag (C, D) and the stitch length/width. If the result doesn't change, the problem might be technical. It's possible the stitches and settings are misaligned, you might need a technician.

You need to adjust the tension.
One of the reasons, if the machine is otherwise fine, is:
The thread thickness doesn't match the fabric thickness
Poor thread quality
The needle thickness doesn't match the fabric thickness
The needle is defective
It's easier to adjust everything on a straight stitch, with a stitch length of 3-4 mm. You can check yourself using a zigzag (if the tension is "off," it's immediately visible there).
And only then test all the types of stitches.
It's easier to use cotton fabric of medium density in 2 layers.

@Milka 223, well, that's a whole different story! A little bit of tinkering and you'll get it all working!