Hello,
Click "stop signing in all Microsoft apps automatically" and give it a bit time to see if the correct display name syncs.
If not, perform a relink and see if it syncs.
Go to Settings > Accounts > Your info
Click on Sign in with local user instead. follow the steps and finish the rest.
(If you don't see the "sign in with a local account instead option, click on "Stop signing into Microsoft apps automatically" first, then relaunch this page. )
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)