It may seem a bit crazy but - fungus Nats survive due to wetness- spray the dirt with the top of soil or cover with neem oil and cinnamon- it won’t affect the plant. Then let it dry out for about 4-5 days- if u get wilting from not watering - just slightly water the top with no runoff. As the neem and cinnamon Work in - they will die so will larvae and whala- no more nats !!
I used everything from DE to yellow traps - to mosquito dunks- and many other things. In the world of all natural - I find neem and cinnamon do the trick. Hope this helps.
Regards,
ThePotFather323