Envato is the worst site regarding tax withheld. I'm from a country that doesn't have a tax treaty with US, so 30% tax should be deducted from my US sales.
If I sell a clip for 100$ on SS, and I'm on level 4, I'll get 30%=30$. If the sale is for a US client, another 30% is deducted from my share and I'm left with 21$. The same happens with Adobe Stock.
If I sell a clip for 100$ on Envato, they will deduct 3$, then I got 50% of the rest = 48.5$. If the sale is for a US client, they will deduct 30% of the whole sale, in this case 30$, from my share, and I will be left with:
48.5$ - 30$ = 18.5$ (!)