Entity Core 2.0.3 Exception: must be reducible node

I am trying to convert the following sql query to EF

sql Query

Select  Sum([KiloWatt]) as 'Sum',
    Min([KiloWatt]) as 'Min',
    Max([KiloWatt]) as 'Max',
    Sum([KiloWatt])/COUNT([KiloWatt]) as 'Average',
    CONVERT(date, [DateTime]) 
from OneHourElectricitys 
where [DateTime] < SYSDATETIME()
group by CONVERT(date, [DateTime])

EF Code

var analytics = await _analyticsRepository.Query().Where(x => x.DateTime.Subtract(DateTime.Today).Days < 0)
                                                  .GroupBy(x => x.DateTime.Date)
                                                  .Select(x => new 
                                                    { DateTime = x.Key, 
                                                      Max = x.Max(y => y.KiloWatt),
                                                      Min = x.Min(y => y.KiloWatt),
                                                      Avg = x.Sum(y => y.KiloWatt)/ x.Count(),
                                                      Sum = x.Sum(y => y.KiloWatt)
                                                    })
                                                  .ToListAsync();

Stack Trace :-

System.ArgumentException: must be reducible node at System.Linq.Expressions.Expression.ReduceAndCheck() at System.Linq.Expressions.Expression.ReduceExtensions()

Am I doing coming wrong?

-- Update --

The following 2 EF queries run fine but combining them gives the error.

var analytics = await _analyticsRepository.Query().Where(x => x.DateTime.Subtract(DateTime.Today).Days < 0)

var analytics = await _analyticsRepository.Query().GroupBy(x => x.DateTime.Date)
                                              .Select(x => new 
                                                { DateTime = x.Key, 
                                                  Max = x.Max(y => y.KiloWatt),
                                                  Min = x.Min(y => y.KiloWatt),
                                                  Avg = x.Sum(y => y.KiloWatt)/ x.Count(),
                                                  Sum = x.Sum(y => y.KiloWatt)
                                                })
                                              .ToListAsync();