Search box not working after upgraded to Windows 10 version 1909


My elder brother planning to roll out v1909 to machines with v1809 of Windows 10. In his current image, each new user has the Search function set to an icon instead of a box. During testing updates, the search box ends up showing up instead of the icon.
He aware of the ActiveSetup registry keys and did test this out when he was first making a v1903 image. When he updated the v1903 computer to v1909, the same behavior occurred with the search box on the taskbar making itself present. he is not aware of a way to re-add the ActiveSetup keys after an update. he was skipping rolling out v1903, but the same behavior would have occurred there as well.
Unfortunately, the “Allow Cortana” GPO only removes the Cortana button from the taskbar, and we already have that rolled out via GPO. he cannot find a GPO that minimizes this Search Box to an icon.
The update is being pushed via Ivanti EPM. The current solution I’ve thought of is to make a query to apply the ActiveSetup registry keys to all machines that match v1909.
he would just prefer the user to never see that search box, as the primary user will see the box as soon as they log in to the freshly updated computer.
Any tips on what to do in this situation would be appreciated!