[Xbox] Xbox.com pre-order driver gear, one code 'already owned'?

Hi. Received my Xbox message yesterday containing two codes for the xbox.com preorder driver gear.

The first code allows me to step through the redeem process all the way up to when I can click CONFIRM add it to my account, but then ‘fails’ with:

Looks like you already own this
Hope you’re enjoying it.
Looks like you already own this Hope you’re enjoying it.
PUR-UserAlreadyOwnsContent
tQySX8UK7xiX2qKqSzGVS2.10
2017/10/05 - 14:58:24 UTC

The second code was able to redeem correctly.

What’s interesting is that the code redemption process is designed to identify whether a code has been redeemed before you move through it (tells you the code is redeemed on the page where you enter it, which is exactly what’s happening with the second code now that I’ve used it). It doesn’t do this with the first code, so the code itself is good (not redeemed) but somehow the system thinks I already have the content?

Besides what’s come with the Ultimate version itself, the only other add on I have for Forza 7 is the driver gear that you can win from the rewards.xbox.com forza motorsport 7 contest. Maybe these are the same? It’s hard to tell because the pre-order details don’t give an idea on what these two driver gear sets look like.

Thanks in advance for your help!

The first code is the same Driver Gear from Xbox Rewards.