Hi,
Based on your description, I know that you cannot find the add-ins in Outlook clients but can see them in the Exchange Management Shell.
To narrow down the issue, I need to confirm:
1. Can you see the add-ins in OWA?
2. What is your Outlook client versions? Did you test the issue in other versions?
Since issue is also related to the Outlook clients, to provide a more professional solution, I recommend you to post another thread in
Outlook IT Pro Discussions.
Best Regards,
Manu Meng
TechNet Community Support
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