Ok after trying a speeker switcher, switching from cinnimon to the kde version, finnally I tried flashing with the offical armbian flasher, and I tried a bunch of old online solutions that looked similar. Still my headphone doesn't work. I think it is due to armbian thinking the built in sound card is the headphones. But on a positive note the weird unmounting of armbian when my chromebook sleeps or when the lid is closed does not occur on armbian kde. So far kde is more stable than cinnimon.