Customer raised an incident stating when he is trying to perform 'Change Ownership' from the record edit screen, he is not getting the owners listed in the dropdown. What could be the issue?

Users will get listed only if the record has earlier traversed through a state which is inherited from ‘Assign’. It means, the record should have been assigned atleast once to a technician for the change ownership to work. Aside, the technician who is trying to perform the ownership change should have the ‘Change owner’ access under any of the role he holds.