Monetized 500+ subs over a month and still 0 revenue

Any ideas ? I could use a little extra $ and I get 600 watch hours and 30k views per month on my long form.. studio overview tab then estimated revenue and it has been at zero for over a month since after monetisation From 500 subs … I’m already almost at 1000 and still haven’t got even a penny on the estimated revenue … please help someone?