Mitel Personal Contacts on iPhone Micollab and Mac Micollab not always working

[Germs]

Hi

we have a small business and we are sharing our contacts (over 2000) through the Apple contacts app. All Contacts show up under the Tab Personal Contacts in the Micollab app.

However ,sometimes a person calls us , and the Micollab on the Mac displays the name , but the iPhone displays the Number.
Sometimes , it just works on both . We have not found the solution to the problem , and our service provider doesn't know the issue either.

Anyone who can help me ?

Thanks