@Bobby_Long you have the same question in this thread Getting multiple contact by email to then retrieve value of custom field. If possible please don’t create new threads for the same question.
So to your question, if you are 100% sure _LoanStaus works when fetching by id, but not by email. I would double check that email is not associated to an actual user in the system. We filter users out for findByEmail. An empty response makes me think that the email address on the contact is not what you think it is or it is associated with a user not a regular contact.