I used m420 after m28 and m29 , not at the very end of the code. I will try again tho i,thank you.
Plus i will add the z offset number with the z offset wizard of Merlin. i had it zero untill now ( like the most of YouTubers ) . I hope this make the difference.

Btw do you know how the " fade " and "mesh" can affect the print ? There are some standard values for this characteristics?
At one forum i saw that if you have warped bed its good to set the "fade " value between 15-20. Is that right ?