$expand not working with ODataQueryOptions in the backend

[renatolombardo]

I have a controller which has OdataQueryOptions as a parameter, as follows:

[EnableQuery]
public async Task<ActionResult<IEnumerable<SecuredEmployee>>> Get([FromQuery] int? managerLevel,
                                                                  [FromQuery] string? managerEmployeeNumber,
                                                                  [FromQuery] bool isSearch = false,
                                                                  ODataQueryOptions<SecuredEmployee>? options = null)
{
    var userId = "[email protected]";
    isSearch = true;

    var employees = await mediator.Send(new ListEmployeesQuery(managerLevel, managerEmployeeNumber, userId, isSearch: isSearch), CancellationToken.None);

    var filteredResults = options?.Filter.ApplyTo(employees.AsQueryable(), new ODataQuerySettings()) as IQueryable<SecuredEmployee>;

    var expandedResults = options?.SelectExpand.ApplyTo(filteredResults, new ODataQuerySettings()) as IQueryable<SecuredEmployee>;

    return Ok(employees);
}

And here is the call:

https://localhost:7145/odata/ExportSearchResults/
        ?$filter=((contains(forename, 'dange')) or (contains(surname, 'dange')) or (contains(employeeNumber, 'dange'))) and (status eq true)
        &$expand=PerformanceReviews,EngagementScores,TalentAssessments,SecuredEmployeeDetails
        &isSearch=true&$top=5&$skip=0&$count=true

After the return Ok(employees), the filter and expand are correctly applied.

Also, filteredResults returns the correct results, with $filter applied. expandedResults returns null.

Here is the SelectExpand property:

And here's the OData configuration:

public static ODataConventionModelBuilder AddODataEntities(this ODataConventionModelBuilder modelBuilder)
{
    modelBuilder.EntitySet<SecuredEmployee>("Employee").EntityType.HasKey(entity => entity.EmployeeId);
    modelBuilder.EntitySet<SecuredPerformanceReview>("PerformanceReview").EntityType.HasKey(entity => entity.Id);
    modelBuilder.EntitySet<SecuredEngagementScore>("EngagementScores").EntityType.HasKey(entity => entity.Id);
    modelBuilder.EntitySet<SecuredTalentAssessment>("TalentAssessments").EntityType.HasKey(entity => new { entity.EmployeeId, entity.Year });
    modelBuilder.EntitySet<TalentAssessmentAuditLog>("TalentAssessmentAuditLogs").EntityType.HasKey(entity => new { entity.EmployeeId, entity.Year, entity.IdentityId, entity.EffectiveDate });
    modelBuilder.EntitySet<SecuredEmployeeDetails>("EmployeeDetails").EntityType.HasKey(entity => new { entity.EmployeeId });
    modelBuilder.EntitySet<SecuredMobilityConsideration>("MobilityConsiderations").EntityType.HasKey(entity => entity.Id);
    modelBuilder.EntitySet<SecuredEmployee>("ExportSearchResults").EntityType.HasKey(entity => entity.EmployeeId);

    return modelBuilder;
}

And the OData statement:

services.AddControllers().AddOData(opt => opt.Count().Filter().Expand().Select().OrderBy().SetMaxTop(100)
    .AddRouteComponents("odata", builder.GetEdmModel()));

The reason is that I'm trying to use the same filter applied in the frontend to export the exact same result to an Excel file, so I need $expand and $filter to work properly. In this case, $expand is not working within the controller. Only after the result is returned.