[cguZZMan]

Looks like this is known issue with display names in outlook/hotmail. It takes a lot for the change to be reflected in the apis. In the meantime you could change the name manually. But you need to modify a file in your system.
Go to the folder Kodi\userdata\addon_data\plugin.onedrive.
In that folder, open the file accounts.cfg,
Search and edit your names.
Save the file.

This will change the display names only in Kodi and should fix your issue.