The fields "category" and "subcategory" are missing from the problem table. We compared with an instance Out of the box and those fields seem to be missing only on our instances. This is affecting both OneLight and OneLightDev instances I could not find any records in sys_metadata_delete or sys_audit_delete representing those fields
Release or Environment
Plugin "Problem Management Best Practice — Madrid" not enabled
The category and sub-category choices are installed with the plugin Problem Management Best Practice — Madrid plugin
In OOB instance, the plugin is per default installed and it will create entries for category and sub-category in the Choice Set [sys_choice_set] table.