I'm not sure that you're saying users are added to the domain admin group in AD. Hope I'm just reading it wrong, and you have a group called Administrators that is used for access.
Anyway, I couldn't reproduce the issue on my lab.
Spun up a clean install of Windows 11, logged in with a domain administrator account and the permissions were there, as the domain admins group is part of the local administrators.
Maybe review the groups the user is part of in AD, and see if any of the groups is a member of the local administrators group on the workstation.
If it isn't, consider adding the relevant group via GPO (Computer Configuration -> Policies -> Windows Settings -> Security Settings -> Restricted Groups)
If this should already happen, and has worked in the past, maybe check if the policy applies to the OU where the computer object is.