Unable to un-hide users from GAL

We have user mailboxes in O365.
Some email users mailboxes are hidden from address list and I wan't to un-hide them
When I try to do this from O365 console then get the following error :-
"The operation on mailbox failed because it’s out of the current users’s write scope. The action ‘Set-Mailbox’, ‘HiddenFromAddressListsEnabled’, can’t be performed on the object because the object is being synchronized from your on-premises organization. This action should be performed on the object in your on-premises organization."

I can't modify the "msExchHideFromAddressLists" attribute for these user accounts as this attribute does not exist on the on-premises domain controllers.

How can this issue be resolved? Meaning how can I make these users appear in GAL?