@Anonymous
Hi there! So, here's what I think is happening -
Let's say you've got 10 contacts in Outlook, and when something is added to the SharePoint contacts list, it starts comparing them like this:
Does the SharePoint contact match contact number 1? Yes or no?
Does the SharePoint contact match contact number 2? Yes or no?
Does the SharePoint contact match contact number 3? Yes or no?
Does the SharePoint contact match contact number 4? Yes or no?
and so on...
So even if there is a match in your Outlook contacts, it is going to add 9 more new contacts as it compares. And it will get exponentially worse with each run.
Here's a thread where we ran into the same issue with Planner tasks, there might be a solution in either of the two offered there. Either way, please keep us posted.
-Ed-
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