Hey there
Maybe u don't have enough views per video sure when u get more views to the video it mean that more skipAd press and more closing the small ads and also means more revenue.
Do u even know how it is going on!! mean how u get money from videos!?
iv made rev by ten views before and one of my recent vids hit 200 i know how it works because i looked into it for i got into youtube i did my research