To better help you, I want to confirm that do these shared files with function controls work successfully in Excel desktop app?
Have you tried to use OneDrive for Business or SharePoint to share these Excel files and set "view only"?
If these function controls don't work on Excel online, you can try to let users open these files using the Excel client as default. For more about such settings, please refer to following thread.
How to put Office Excel to open a file in SharePoint
Besides, if one people in the team shares files useing an organization account to others in the same tenant, recipients can find these shared files directly in their OneDrive for Business online > Shared > Shared with you.
But if you still want to use Teams to share files, it's better to open a new thread on Q&A forum with tag "Microsoft Teams".
In addition, if these shared Excel files can not work successfully because of "view only" permission, I am afraid you need to give more permission to shared users.
Thanks for your understanding.
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