Outlook on Android issue with sync contacts added in Outlook on phone

We notice that when we add Contacts to Outlook on our desktops the contacts get synchronized to our Outlook app on Android and all contact information is also synchronized to the Contact app on Android.

However, when we search a user in the Outlook app and add this user to our Contacts (within the app) only part of the information gets synched to Contacts. Phone nummer for instance is missing !!

Does anyone have an idea ?