EXCEPTION: Unsupported filter when comparing fields in a collection

I'm trying following query:

 var modifiedOrders = await _applicationUnitOfWork.OrderRepository.Find(a => a.createdDate!= null && a.lastUpdated != (a.createdDate ?? DateTime.UtcNow)).SortBy(x => x.createdDate).ToListAsync();

But getting following error:

EXCEPTION: Unsupported filter: ({document}{lastUpdated} != ({document}{collectionDate} ?? 05/26/20 22 15:09:41)).

Any one has any solution?