These two fields were modified in a recent update. Prior to the update, when on the "Department" field, pressing tab would put the focus on the "Site" field, then on the "Technician" field, and then on the "Category" field. Now the two affected fields are skipped, going from "Department" to "Category" directly. And if you cycle the full tab order of the form, the two fields are never touched.
Please review and solve this. It is just renumbering the tab order, this task should not take a developer more than 5 minutes.