One technician we can't modify the Roles assignment - Its not available to make changes

One technician we can't modify the Roles assignment - Its not available to make changes

Hello,

One of the technician we can't modify the Roles assignment. Its not even available as a selection to change.
Also, the selection box to change it back to Requester is also not available.

How to do I fix this?
                New to ADManager Plus?

                  New to ADSelfService Plus?