When validating the property, the user context will be the solution user for the vRA appliance rather than the context of the submitting user. Thus, when the customer action is considering user context, the values displayed in the request form can vary from the values returned during validation, which causes the failure.
Resolution
This issue is resolved in VMware vRealize Automation 7.4, available at VMware Downloads.
To workaround this issue, if the property filtering cannot be altered, vRealize Orchestrator action should return all expected values when the solution user has encountered.
Note: The name of the solution user is unique for every installation, but will start with word cafe.
For example: cafe-nwrsei32pQ. You can confirm the name in the following file on the vRealize Automation appliance: