I’m having an issue while using automapper.

following is the relevant code

if (await _appDbContext.PharmaPointEmployees
    .Include(nav => nav.BonusRecords)
    .FirstOrDefaultAsync(dbEntry =>
        dbEntry.EmployeeId == request.EmployeeId &&
        dbEntry.PharmaPointId == request.PharmaPointId,
        cancellationToken)
            is not PharmaPointEmployee pharmaEmployee) return NotFound();
    

/// at this point pharmaEmployee.BonusRecords contains 1 value

request.MapTo(pharmaEmployee);

/// at this point pharmaEmployee.BonusRecords contains 0 values

where MapTo

public static void MapTo<TDestination>(this object source, TDestination destination)
{
    if (_mapper is null) throw new NullReferenceException($"Initialize {nameof(IMapperExtensions._mapper)} at application startup.");

    if (source is null) throw new TypeInitializationException(typeof(TDestination).FullName, null);

    _mapper.Map(source, destination);
}

mapping profile

public class PutEmployeeBonusRecordRequestProfile : Profile
{
    public PutEmployeeBonusRecordRequestProfile()
    {
        CreateMap<PutEmployeeBonusRecordRequest, PharmaPointEmployee>()
            .ForMember(dest => dest.BonusRecords, opt => opt.MapFrom<EmployeePharmaPointsResolver>());
    }

    private class EmployeePharmaPointsResolver : IValueResolver<PutEmployeeBonusRecordRequest, PharmaPointEmployee, ICollection<BonusRecord>>
    {
        ICollection<BonusRecord> IValueResolver<PutEmployeeBonusRecordRequest, PharmaPointEmployee, ICollection<BonusRecord>>.Resolve(
            PutEmployeeBonusRecordRequest source,
            PharmaPointEmployee destination,
            ICollection<BonusRecord> destMember,
            ResolutionContext context)
        {
            if (destination.BonusRecords.FirstOrDefault(
                item => item.EmployeeId == source.EmployeeId &&
                item.PharmaPointId == source.PharmaPointId &&
                item.BonusProgramId == source.BonusProgramId &&
                item.BranchId == source.BranchId)
                    is BonusRecord record)
            {
                record.Agreement.Type = source.BonusType;
                record.Agreement.Value = source.BonusValue;
            }
            else
            {
                destination.BonusRecords.Add(
                    new BonusRecord
                    {
                        BonusProgramId = source.BonusProgramId,
                        BranchId = source.BranchId,
                        EmployeeId = source.EmployeeId,
                        PharmaPointId = source.PharmaPointId,
                        Agreement = new BonusRecordAgreement
                        {
                            Type = source.BonusType,
                            Value = source.BonusValue
                        }
                    });
            }
    
            return destination.BonusRecords;
        }
    }
}

the pharmaEmployee value in the caller indicates that it has one record for BonusRecords, inside the mapper I still can see the value, while also can update the record value. When controll is returned to caller, the pharmaEmployee.BonusRecords is an empty list. How come ?