I saw that this issue has been marked resolved in the Hitman bug thread but I am still unable to access Hitman 1 levels in Hitman 3. I own the Complete Edition of the former (not Goty) and those levels are available in Hitman 2.
However, they are still unavailable in 3. I have tried the access passes and alternative passes suggested by IOI but the Microsoft store still says I have to buy them.
You may make a reply to the following thread, there is an IOI staff who may be able to help you. Alternatively, you can send them a private message as well.