Hi @Rich Morrissey ,
Does this issue persist only on specific user?
Please check if you have changed the AD attribute to hide contacts from GAL. In my experience, if you ser the “msExchHideFromAddressLists” to true, it will hide users from the GAL. For more details, you can refer to:
http://www.uclabs.blog/2017/11/hide-users-from-address-book-in-skype.html
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