U8g2 lib issue printing floats = freeze

Hi all,

I'm running a sketch to read a car wideband sensor to monito combustion.
The bare "measure only and print to serial" works perfectly for hours!

The issue start when I try to print on an Oled display via the u8g2:
Below the part where I print 2x logos in xbmp and 2x float values, wich causes the issue where <2-3min the arduino freezes and the <avr/wdt.h> needs to step in!
I verified free memory with the additional lib and I'am around 700

Any idea if the issue is code or lib based?

u8g2.firstPage();
  do {
    u8g2.clearBuffer();
    u8g2.drawXBMP(4, 4, 20 , 20, HeaterSymbol);
    u8g2.drawXBMP(5, 40, 20, 19, LambdaSensorSymbol);
    u8g2.setFont(u8g2_font_bubble_tr);
    u8g2.setFontDirection(0);
    u8g2.setCursor(35, 22);
    u8g2.print(Lookup_Temperature(adcValue_UR), 0);
    u8g2.setCursor(98, 22);
    u8g2.print(" C");
    u8g2.setCursor(35, 59);
    u8g2.print(Lookup_Lambda(adcValue_UA), 2);
    u8g2.setCursor(117, 40);
    u8g2.setFontDirection(2);
    u8g2.print(" Y");
    u8g2.sendBuffer();
  } while ( u8g2.nextPage() );

Total sketch specs;
Sketch uses 23490 bytes (72%) of program storage space. Maximum is 32256 bytes.
Global variables use 1400 bytes (68%) of dynamic memory, leaving 648 bytes for local variables. Maximum is 2048 bytes.

Please post your entire sketch.