async and group by queries get an error

[apis3445]

Steps to reproduce

Hi! I have some queries with a group by and async operator like this
` ```
var qryIndicadores = (from indicador in contexto.Indicador.Where(x => x.EmpresaId == id)
join ResponsableResultado in contexto.ResponsableIndicador.Where(x => x.Tipo == responsable)
on indicador.Id equals ResponsableResultado.IndicadorId
join Puesto in contexto.Puesto
on ResponsableResultado.PuestoId equals Puesto.Id
group new { indicador, Puesto } by indicador into grupo
select new IndicadorValoresDTO
{
Id = grupo.Key.Id,
Clave = grupo.Key.Clave,
Nombre = grupo.Key.Nombre,
Polaridad = grupo.Key.Polaridad,
AcumuladoForma = grupo.Key.AcumuladoForma,
Unidad = grupo.Key.Unidad,
Responsables = grupo.Select(t =>
t.Puesto.Nombre
).ToList(),
ResponsablesDTO = grupo.Select(t => new BusquedaDTO
{
Id = t.Puesto.Id,
Nombre = t.Puesto.Nombre,
Clave = t.Puesto.Clave,
}),
}).ToListAsync();

           `
and I get an error, If I don't use async await with the same query I get the error

### The issue
The query with async an await with group by gets an error

Exception message:
Expression of type 'System.Collections.Generic.IAsyncEnumerable1[System.String]' cannot be used for parameter of type 'System.Collections.Generic.IEnumerable1[System.String]' of method 'System.Collections.Generic.List1[System.String] ToList[String](System.Collections.Generic.IEnumerable1[System.String])'
Parameter name: arg0
Stack trace:
at System.Dynamic.Utils.ExpressionUtils.ValidateOneArgument(MethodBase method, ExpressionType nodeKind, Expression arguments, ParameterInfo pi, String methodParamName, String argumentParamName, Int32 index) at System.Linq.Expressions.Expression.Call(MethodInfo method, Expression arg0) at System.Linq.Expressions.MethodCallExpression1.Rewrite(Expression instance, IReadOnlyList1 args)
at System.Linq.Expressions.ExpressionVisitor.VisitMethodCall(MethodCallExpression node)
at System.Linq.Expressions.MethodCallExpression.Accept(ExpressionVisitor visitor)
at System.Linq.Expressions.ExpressionVisitor.Visit(Expression node)
at System.Linq.Expressions.ExpressionVisitor.VisitMemberAssignment(MemberAssignment node)
at System.Linq.Expressions.ExpressionVisitor.VisitMemberBinding(MemberBinding node)
at System.Linq.Expressions.ExpressionVisitor.Visit[T](ReadOnlyCollection1 nodes, Func2 elementVisitor)
at System.Linq.Expressions.ExpressionVisitor.VisitMemberInit(MemberInitExpression node)
at System.Linq.Expressions.MemberInitExpression.Accept(ExpressionVisitor visitor)
at System.Linq.Expressions.ExpressionVisitor.Visit(Expression node)
at Microsoft.EntityFrameworkCore.Query.EntityQueryModelVisitor.ReplaceClauseReferences(Expression expression, IQuerySource querySource, Boolean inProjection)
at Microsoft.EntityFrameworkCore.Query.EntityQueryModelVisitor.VisitSelectClause(SelectClause selectClause, QueryModel queryModel)
at Microsoft.EntityFrameworkCore.Query.RelationalQueryModelVisitor.VisitSelectClause(SelectClause selectClause, QueryModel queryModel)
at Remotion.Linq.QueryModelVisitorBase.VisitQueryModel(QueryModel queryModel)
at Microsoft.EntityFrameworkCore.Query.EntityQueryModelVisitor.VisitQueryModel(QueryModel queryModel)
at Microsoft.EntityFrameworkCore.Query.RelationalQueryModelVisitor.VisitQueryModel(QueryModel queryModel)
at Microsoft.EntityFrameworkCore.Query.EntityQueryModelVisitor.CreateAsyncQueryExecutor[TResult](QueryModel queryModel)
at Microsoft.EntityFrameworkCore.Query.Internal.CompiledQueryCache.GetOrAddQueryCore[TFunc](Object cacheKey, Func1 compiler) at Microsoft.EntityFrameworkCore.Query.Internal.QueryCompiler.ExecuteAsync[TResult](Expression query) at Microsoft.EntityFrameworkCore.Query.Internal.EntityQueryable1.System.Collections.Generic.IAsyncEnumerable.GetEnumerator()
at System.Linq.AsyncEnumerable.<Aggregate_>d__63.MoveNext() --- End of stack trace from previous location where exception was thrown --- at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw() at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task) at System.Runtime.CompilerServices.TaskAwaiter1.GetResult()
at Caltic.Controllers.Gestion.CsvController.d__13.MoveNext() in D:\docs\0214net\Caltic\Caltic\Controllers\Gestion\CsvController.cs:line 195
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at Microsoft.AspNetCore.Mvc.Internal.ActionMethodExecutor.TaskOfIActionResultExecutor.d__0.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at Microsoft.AspNetCore.Mvc.Internal.ControllerActionInvoker.d__12.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at Microsoft.AspNetCore.Mvc.Internal.ControllerActionInvoker.d__10.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
at Microsoft.AspNetCore.Mvc.Internal.ControllerActionInvoker.Rethrow(ActionExecutedContext context)
at Microsoft.AspNetCore.Mvc.Internal.ControllerActionInvoker.Next(State& next, Scope& scope, Object& state, Boolean& isCompleted)
at Microsoft.AspNetCore.Mvc.Internal.ControllerActionInvoker.d__13.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at Microsoft.AspNetCore.Mvc.Internal.ResourceInvoker.d__24.MoveNext()`

Further technical details

MySQL version: 5.7
Operating system: Windows Server 2016
Pomelo.EntityFrameworkCore.MySql version: 2.1.1

Other details about my project setup:

[mguinness]

Could be related to upstream issue found at dotnet/efcore#12449.