Do all users not able to view the list in 'contact' page? According to your information above, your issue seems to be related to the GAL. We could consider creating a new GAL in O365, then create and assign a new address book policy which include the new created GAL to a test user to test the result.
Just like the process introduced in this article: OFFICE365 CREATE GLOBAL ADDRESS LIST
Please Note: Since the web site is not hosted by Microsoft, the link may change without notice. Microsoft does not guarantee the accuracy of this information.
For more information, refer to the official document here: Create a global address list in Exchange Online
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