Hello Brady Wheeler,
Welcome to Microsoft Q&A forum.
Before we proceed, may I know the option you see in the Sign-in preferences menu? Do you see any options to edit the primary email? Recently, I've seen reports that the Make primary button has been removed, so can you try to see if you can remove the intended alias and then use the edit button to make it the primary email instead?
If you want to contact Microsoft Support, you can try to use this method.
- Type Live chat in the search box.
- Now click Get help, and Select Contact Support or Sign in to contact support below.
- Go to the Products and services tab, and choose Other products
- On the Category tab, choose Billing and Account Profile questions
- Go to Confirm.
- You can now choose the option of Chat with a support agent on your web browser.
Thank you for your understanding.