Why gameflip have too many " under review " ?
They are verifying payment methods. You dont have to do anything about it. Simply wait for buyers payment to process. If they cancel your listing is automatically back on sale.
The payment come from high risk source, look like they are using stolen credit card… Gameflip will automatic under review for verify it clean and safe for your transaction.
I also have Under Review only with $100 gift card i’m selling.