Failed to decode and unexpected behavior with custom configuration

Hi. I tried to conduct some tests to determine the most suitable parameters for my printer and scanner. I succeeded in compiling the project on my M2 chip Mac, and the printer/scanner I use is an Apeos C6570, which is supposed to print/scan with 600+ dpi. I choose a file and then use five different settings of `XCROSSES` and `YCROSSES` to compile, and then print/scan on A4 paper using the same parameters. Here is the decode result:

Group|XCROSSES|YCROSSES|rate% of irreparable
:---:|:---:|:---:|:---:
1|65(default)|93(default)|9.8574
2|59|84|51.5284
3|52|74|51.6052
4|46|65|51.5284
5|39|56|51.8302

It can be noticed that the proportion of irreparable behaves very strangely (rising and extremely close). Here I attach the 100% zoom of scans from group 1 and group 5:

Any idea for the reason? Thanks for any suggestions.