Missing Adventure Themes on Character Sheet

Hey,

I own Baldur's Gate: Descent into Avernus but I do not have any of the themes or frames from it. How do I troubleshoot this?

Did you pre-order it? The frames and backgrounds are a pre-order bonus, not a general purchase bonus

I believe I did. I definitely had to wait for it to unlock so was there a cut off for pre-order bonus before the official release?

Shouldn't be a cut off, just if you paid before release. I'd check your purchase history and make sure the purchase went through before the release date. If it did, then contact customer support.