As far as I’m aware, the payout should be 30% for taxes (unless you are in a country with a treaty, in which case it is lowered) and 10% (default) for Itch. I’m not aware of any extra charges, but I don’t know if donations are treated the same as actual payments. Could your payment method be charging something extra?

Also, can I still adjust the revenue sharing after such a long time? Might raise it a little bit higher because this is just a very great platform.

You should be able to change the revenue at any point without any issue. To do that go to “Account Settings” -> “Publisher” -> “Revenue sharing”. There you can adjust a slider for what percentage to give to Itch. I’m not sure if this happens at the moment of a purchase, or once you request a payout.

Hiya there!

For each payout on the payout page, there should be a link to view more details around it; 'Payout Details'.

There you'll see all the different adjustments that go into the payout amount before it's sent to you. Such as tax, itch'io's cut, payment processor fees, and then a bunch of additional things that could potentially be affecting things, such as chargebacks, refunds and the additional payout fee.

Hopefully that'll help to get to the bottom of things regarding any potential deductions!