When searching for objects in the Assets field, any ORDER BY added to the filter scope or filter issue scope in field configuration is ignored, so the results displayed are ordered by the label attribute, as described on https://support.atlassian.com/jira-service-management-cloud/docs/use-insight-query-language-iql/#Ordering.

Suggestion:

Respect ORDER BY clauses added to filter scope and/or filter issue scope in field configuration (one will have to take priority over the other). Or alternatively, provide an explicit option in field configuration to choose the attribute and direction to order by.