I think I have solved the issue. I believe the account was considered a "minor" account, even though I have set the date of birth to be above 18. After contacting xbox.com, they told me to change the birth year to 2000. After making this change, signing into xbox.com was no longer an issue, and I was able to sign into the alt manager. Everything seems to be working now. Thank you for helping me with this problem. Have a good one!
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