efcore: System.NullReferenceException thrown

I have an OData query like: ...Bikes(1)/ns.MountainBike?$expand=Children($select=P1,P2,ns.A/P3,ns.B/P4)

Some of the instances in Children are of type A, none are of type B.

Unfortunately this exception is being thrown:

System.NullReferenceException: Object reference not set to an instance of an object.
   at lambda_method36509(Closure , QueryContext , DbDataReader , ResultContext , ResultCoordinator )
   at Microsoft.EntityFrameworkCore.Query.RelationalShapedQueryCompilingExpressionVisitor.CustomShaperCompilingExpressionVisitor.
<PopulateCollection>g__ProcessCurrentElementRow|7_1[TCollection,TElement,TRelatedEntity](<>c__DisplayClass7_0`3& )
   at Microsoft.EntityFrameworkCore.Query.RelationalShapedQueryCompilingExpressionVisitor.CustomShaperCompilingExpressionVisitor.PopulateCollection[TCollection,TElement,TRelatedEntity](Int32 collectionId, QueryContext queryContext, DbDataReader dbDataReader, ResultCoordinator resultCoordinator, Func`3 parentIdentifier, Func`3 outerIdentifier, Func`3 selfIdentifier, IReadOnlyList`1 parentIdentifierValueComparers, IReadOnlyList`1 outerIdentifierValueComparers, IReadOnlyList`1 selfIdentifierValueComparers, Func`5 innerShaper)
   at lambda_method36510(Closure , QueryContext , DbDataReader , ResultContext , Int32[] , ResultCoordinator )
   at Microsoft.EntityFrameworkCore.Query.Internal.QueryingEnumerable`1.Enumerator.MoveNext()
   at Microsoft.AspNet.OData.EnableQueryAttribute.SingleOrDefault(IQueryable queryable, IWebApiActionDescriptor actionDescriptor)
   at Microsoft.AspNet.OData.EnableQueryAttribute.ExecuteQuery(Object responseValue, IQueryable singleResultCollection, IWebApiActionDescriptor actionDescriptor, Func`2 modelFunction, IWebApiRequestMessage request, Func`2 createQueryOptionFunction)
   at Microsoft.AspNet.OData.EnableQueryAttribute.OnActionExecuted(Object responseValue, IQueryable singleResultCollection, IWebApiActionDescriptor actionDescriptor, IWebApiRequestMessage request, Func`2 modelFunction, Func`2 createQueryOptionFunction, Action`1 createResponseAction, Action`3 createErrorAction)
   at Microsoft.AspNet.OData.EnableQueryAttribute.OnActionExecuted(ActionExecutedContext actionExecutedContext)
   at Microsoft.AspNetCore.Mvc.Filters.ActionFilterAttribute.OnActionExecutionAsync(ActionExecutingContext context, ActionExecutionDelegate next)
   at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.
    <InvokeNextActionFilterAsync>g__Awaited|10_0(ControllerActionInvoker invoker, Task lastTask, State next, Scope scope, Object state, Boolean isCompleted)
   at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.Rethrow(ActionExecutedContextSealed context)
   at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.Next(State& next, Scope& scope, Object& state, Boolean& isCompleted)
   at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.InvokeInnerFilterAsync()
--- End of stack trace from previous location ---
   at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.
        <InvokeFilterPipelineAsync>g__Awaited|19_0(ResourceInvoker invoker, Task lastTask, State next, Scope scope, Object state, Boolean isCompleted)
   at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.
            <InvokeAsync>g__Awaited|17_0(ResourceInvoker invoker, Task task, IDisposable scope)
   at Microsoft.AspNetCore.Routing.EndpointMiddleware.
                <Invoke>g__AwaitRequestTask|6_0(Endpoint endpoint, Task requestTask, ILogger logger)
   at Microsoft.AspNetCore.Authorization.AuthorizationMiddleware.Invoke(HttpContext context)
   at Microsoft.AspNetCore.Authentication.AuthenticationMiddleware.Invoke(HttpContext context)
   at Microsoft.AspNetCore.Diagnostics.DeveloperExceptionPageMiddleware.Invoke(HttpContext context)

If I do this query instead, it works fine: ...Bikes(1)/ns.MountainBike?$expand=Children($select=P1,P2,ns.A/P3)

If I do this query, I get the same exception: ...Bikes(1)/ns.MountainBike?$expand=Children($select=ns.B/P4)

Therefore it looks to me like if I use a cast for a type of which no instances match, I get the exception.

Is this enough information, because it takes a lot of time for me to make a concrete sample which demonstrates it?

I use Microsoft.AspNetCore.OData 7.4.1 and .Net 5.0 preview 5.