Hello K, this is Emily.
Are you signing into your computer using your Microsoft account, or is it a local user?
If you sign in using your Microsoft account, method 1 is indeed the way to go. It is not right that it doesn't sync over. Go to Settings > Accounts > Your Info Do you see "Stop signing into Microsoft apps automatically"? If so, click on it, restart the computer and see if it works. If not, try to relink your Microsoft and see if it works. Here is how you relink:
Go to Settings > Accounts > Your info
Click on Sign in as local user instead. follow the steps and finish the rest
Restart the computer (Do Not skip)
Go to Settings > Accounts > Your info
Click on Sign in with Microsoft account instead. follow the steps and finish the rest
Restart the computer (Do Not skip)
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Now, if you use local user to sign into your Windows, these are the steps you do:
Hold down Windows + R keys, type in netplwiz and hit enter.
Double click on your username, then you can put your name in the Full name field.