Problem: GamePass Ultimate 4 month subscription instead of xbox live Gold 12 month (code)

So my regular subscription will just continue after the 6 months is up?

No. If you already had xbox live gold then when you add an xbox gamepass ultimate subscription (which includes Xbox live gold) it upgrades your existing Xbox live gold subscription to gamepass ultimate (hence why your gold subscription "disappeared")

So lets say for example before you added the gamepass ultimate subscription you had 6 months of xbox live gold left. When you added the 6 month gamepass code youd essentially now have 12 months of gamepass ultimate in this above example.

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.

So I just entered the code to reload my account with 12 months of Gold, but when I did it, It instead gave me 4 months of Game Pass Ultimate? Is there a way to revert this? Because I don't really want the game pass, I just want Gold for the next year..

Did you already have an active gamepass ultimate subscription when you redeemed the year of gold? If so then thats why it converted your 1 year of gold to 4 months of gamepass ultimate.

Look, I bought a 1 month gamepass ultimate but the time is up. The problem is I don't want the gamepass ultimate but instead I want 3 months live gold would it allow me to buy it or would it just extend the gamepass ultimate subscription by 3 months

Hi, if you had redeemed an xbox live gold for 12 months while you had an active Gamepass Ultimate Subscription, all the gold months have been converted to 4 months of Gamepass Ultimate

https://www.xbox.com/en-us/xbox-game-pass#join

In order to get only the Gold subscription you should have waited until GP Ultimate expiration and then redeemed the code... you can try to contact the support and ask them if they can convert your Ultimate subscritpion into a Gold one, but I don't know
if they can do it... https://support.xbox.com/help/subscriptions-billing/manage-subscriptions/xbox-game-pass-faq