@robski - got it solved, turns out the problem was that i was connecting to usb-c on my laptop, which didn't seem like it should be a problem since the Atom Lite also uses usb-c. But once i changed over to my usb-a port, it's all working fine.

@felmue Thank you.
We are struggling really hard with the M5Unified library. We tried getting things working using startwrite and endwrite at the correct places, and also without using (as you suggested). The problems that we are facing is that sometimes the display lights up after a restart and sometimes it does not. We dont believe it is a faulty device because we se it happening with different M5Core2.

We are diving into it. Maybe i will make a new post discribing the problems (and hopefuly solutions) that we are facing with M5Unified.
For now, we dont dare to update our devices in the field because there is no turning back.
Regards