I think I might have been unclear.
The initiator/requestor is a synchronized user, has both AD and AAD user accounts. Both are in Adaxes.
The approver is a synchronized user, has both AD and AAD user accounts. Both are in Adaxes.
The security group is purely AAD based, has the approver as manager.
When logging on as the approver the approval is nowhere to be seen because Adaxes treats the AD and AAD as two different user accounts.
Is this still impossible?