why are most digital purchases from xbox 360 completely gone from my account?

For context we do not have an xbox 360 anymore, however own an xbox series x and are certain that a lot of our digital library is indeed backward compatible. Regardless, they should still exist, right?

We checked all the various microsoft "stores" (xbox, web, windows) and saw no purchase history before 1 jan 2019. We are 100% sure that it is on the correct microsoft account, as the 360 profile still exists with all its gamerscore and gamertag and whatever. These are not games with gold or some silly subscription either, these were cold hard purchases done on the console, on that account. We even tried a trick on the accounts.microsoft page to switch 7Years to AllTime but it didn't work. We are also certain that these games were not purchased on local accounts, because it used a saved card on the actual account.

I would also like to mention that one game that isnt in our leftover purchase history is still present to be downloaded on the console. So we're not sure why the rest are just gone. Is there any way to troubleshoot this before messing with all the ai emails at microsoft's support? We also actually repurchased a game that was taken away and the money was happily taken away (we're not asking for a refund on that though, that would be a seperate issue).