XBOX Live Gold expired before it should because of Ultimate Game Pass

It sounds like you have Xbox Live Ultimate, then purchasing Game Pass Core (Xbox Live Gold) for 12 months, which basically converted to ultimate for 4 months. Which is exactly what it is meant to do. If you wanted the 12 months, then you should have waited for Game Pass Ultimate to Expire before Redeeming the Game Pass Core. There is nothing that you can do. If you cancel Game Pass Ultimate, you will lose Your subscription, including the Game Pass Core you have just redeemed. You're better off waiting until it expires before getting another subscription.

Oh that's sad. Thank you for reply!

Hello! unfortunately as the 2 subscriptions are merged, if you unsubscribe you'll have to buy a new gold subscription.

Hi! it should be 2€ for 2 months. About the expiration date, did you subscribe to game pass or game pass ultimate? Because if you subscribed to Ultimate and have a gold sub, it will merge the two, thus making it expire
in 2020.

If you currently have Game Pass Ultimate and attempt to redeem a 12 month Xbox Live Gold code, it will convert to a 3 or 4 month Ultimate subscription. If you want to continue with just Gold for 12 months and not Ultimate, you would have to wait for the
Ultimate to expire before redeeming the regular Gold code.

If you don't currently have Ultimate, then you should have no problem redeeming the 12 months of Gold.