Was hat meine Pflanze?

I agree completely with Mr_Weeds_Auto. I would do every single one of those steps he recommends because that's what worked for me for house plants with similar issues.

Hey Growmie, those specks on the leaf look like early signs of a fungus gnat issue or possibly thrips, especially since you’ve seen little black flies around. Fungus gnats hang around moist soil and their larvae can mess with your roots, while thrips suck on the leaves and leave silvery or speckled damage like that. Sprinkling cinnamon is a good natural antifungal move and can help deter gnats, but it won’t fully stop them. Sticky traps are solid enough to place a few at soil level and a couple hanging to catch adults. Here’s what else you can do: Let the top inch of soil dry out more between waterings Add a layer of sand or diatomaceous earth to the topsoil to block egg laying Consider BTi (like Mosquito Bits) in water for larvae, or a neem oil soil drench and light foliar spray during lights off if it gets worse You caught it early, so you're not in danger yet, but stay on it before they take over.