strange lines in RepRap Discount FULL GRAPHIC Smart Controller (no replies)

I have strange lines in the 128x64 display with Marlin 2.0.
I had also the problem with Marlin 1.9 but that I have solved with changing this rule:

  
 U8GLIB_ST7920_128X64_RRD u8g(0); // Number of stripes can be adjusted in ultralcd_st7920_u8glib_rrd.h with PAGE_HEIGHT              original line
 U8GLIB_ST7920_128X64_1X u8g(23,17,16); // Number of stripes can be adjusted in ultralcd_st7920_u8glib_rrd.h with PAGE_HEIGHT        changed line

I read on youtube that this was the solution : change first line into the second line.
These line where located in " ultralcd_impl_DOGM.h. "
In Marlin 2.0 didn't I have the file or I can find it.
Can anyone help me to solve this problem in Marlin 2.0