unable to manage service for presales project

In trying to extend the base/studio maintenance services for lululemon-dam-rfp-2023-08 (part of the nuxeo-presales-us connect client), the account management UI just spins on the "Service" tab.

Browser shows an error of `Uncaught (in promise) Error: GraphQL error: Cannot return null for non-nullable type: 'String' within parent 'Service' (/services[302]/endDate)`