Hello joeb xander,
Sorry about the trouble with the gift. It's frustrating to get stuck at checkout, especially after you've already tried clearing the cache, a private window, and your phone. I'm just a fellow user here, so I can't see your account or why the payment is being blocked, but these are the things I'd check.
- Make sure you and your friend are in the same country or region. Gifts can only be bought and redeemed within the same one: https://www.microsoft.com/en-SG/store/b/giftterms
- Check that the payment method is current and matches your Microsoft account's region, and that the account isn't suspended or has no overdue payments: https://support.microsoft.com/en-us/accounts-billing/troubleshoot-buying-issues-with-microsoft-store
- Try not to retry the payment many times in a row. I'm not sure it's documented, but a moderator on a similar thread said it could look like fraud.
- Try gifting from the Xbox app, as the comment above suggested. Search for the game, select "…" > "Buy as gift", then send it by Xbox friend or email: https://news.xbox.com/en-us/2025/12/05/how-to-buy-a-digital-game-as-a-gift-this-holiday-2025/ I can't promise it avoids this error, but it's an official gifting route.
- If checkout keeps failing, buy a Minecraft prepaid card or digital code from a reputable retailer and send the code to your friend. That skips this checkout entirely.
If none of that works, only Microsoft Support can see why the payment is being declined. This forum can't look into it or fix it, so please contact them through the page below: https://support.microsoft.com/home/contact
Sorry I can't do more from here, but I hope one of these gets the gift sent.