Work Schedule is not delivered although set in the employee

When retrieving the list of employees over /v1/company/employees the work schedule for at least one employee is not returned by the API call, although it is set in the frontend.

The API returned the following today at 2023-11-28 07:59:27

[...]
"work_schedule": {
"label": "Work schedule",
"value": [],
"type": "standard",
"universal_id": "work_schedule"
},
[...]