DueVGA library not working correctly

Hello everyone,

I have a problem with video outputting on my old Czechoslovakian TV (Tesla MERKUR 2, made in 1989, PAL) using an Arduino DUE with DueVGA library on it. Picture on the TV is distorted - see photo below.

Code used:

#include <VGA.h>

void setup() {
  
  VGA.beginPAL();
  
  VGA.println("012345678901234567890123456789012345678");
  VGA.println("012345678901234567890123456789012345678");
  VGA.println("012345678901234567890123456789012345678");
  VGA.println("012345678901234567890123456789012345678");
  VGA.println("012345678901234567890123456789012345678");
  VGA.println("012345678901234567890123456789012345678");
  VGA.println("012345678901234567890123456789012345678");
  VGA.println("012345678901234567890123456789012345678");
  VGA.println("012345678901234567890123456789012345678");
  VGA.println("012345678901234567890123456789012345678");
  VGA.println("012345678901234567890123456789012345678");
  VGA.println("012345678901234567890123456789012345678");
  VGA.println("012345678901234567890123456789012345678");
  VGA.println("012345678901234567890123456789012345678");
  VGA.println("012345678901234567890123456789012345678");
  VGA.println("012345678901234567890123456789012345678");
  VGA.println("012345678901234567890123456789012345678");
  VGA.println("012345678901234567890123456789012345678");
  VGA.println("012345678901234567890123456789012345678");
  VGA.println("012345678901234567890123456789012345678");
  VGA.println("012345678901234567890123456789012345678");
  VGA.println("012345678901234567890123456789012345678");
  VGA.println("012345678901234567890123456789012345678");
  VGA.println("012345678901234567890123456789012345678");
  VGA.println("012345678901234567890123456789012345678");
  VGA.println("012345678901234567890123456789012345678");
  VGA.println("012345678901234567890123456789012345678");
  VGA.println("012345678901234567890123456789012345678");
  VGA.println("012345678901234567890123456789012345678");
  
}

void loop() {
  
}

Any help will be very appreciated.