I recently switched over to a new Xbox from my very old one and it says I don't own COD...

Since you said in your original post that your brothers bought COD, then it is the that owns it not you. They would have to sign in with their account to download the game. Things that are purchased on other accounts would not show up in your library since you don't actually own it.

I tried looking through my Account history of purchases but Can't find it so I think it was purchased on a different account but I don't think that's the case because I did purchase a different item on the Old Xbox and I knew it was on this account but ever since I switched Xbox consoles I don't own the item nor is it on my purchase history and i never cleared it. I hope you can help me find a solution to this because this has been a confusing journey for me.

Hi and thanks for reaching Microsoft Xbox gamer's community. My name is Josef.
I'm an Independent Advisor and a Microsoft Xbox user like you.

Hope you're doing great today despite this Jaiden3299

Exists the possibility that the game was purchased with a different account. Let's try to find the account used to purchase this game

For this please go to your Microsoft account order history
https://account.microsoft.com/billing/orders

Once there, make sure to change the "3 months" filter and use instead "All available" next to "Ordered within"
Then start looking each item purchased with your account and see if you're able to find the game with order status "completed"

If you have more than one email please check the order history with each one

Ok I think I see the problem here

I forgot that I had a different email under my Xbox account before I made a new Microsoft account and the Xbox account was never put under the new one

From here on out it seems simple enough to just put the credit card on the old account but before that I tried to switch over to the new account and it says that I already have an account under the new account

Error 80154013

I don't know I'm just going to use the old email

Hello, I went to the store on my new Xbox and it says that I own the dlcs but I don't own the game whereas on my old Xbox it shows that I own the game and dlcs, any reason this is happening? (I do have the new Xbox set as the home Xbox)