Using Classic Outlook on Windows for personal email, calendar, and contact management
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Is there a way, using a shared mailbox, to prevent the messages going to the users inbox (thereby only going to the inbox in the shared mailbox folder)?
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May I double confirm whether you have created Shared mailbox or Group mailbox?
Generally, using a Shared mailbox, email messages will not deliver to your regular inbox unless you have created any forwarding rules. This behavior is expected if you are using an Office 365 Group mailbox.
Moreover, share detailed information on how you created a shared mailbox for further analysis.