LCD displays image for 3 seconds only but backlight stays on

Hi there,

I am having an issue with an MacBook air M1. The LCD displays a perfect image but only for 3 seconds and turns off. The backlight stays on as it should and I can adjust the brightness too. I can repeat the issue as long as I either close and open the lid or hit a key on the keyboard.

I thought about the lid sensor, but it seems to work normally. The computer works normally with an external monitor, and is able to recognise it's own LCD and switch to single monitor mode whenever I close it.

Thanks for your help!