A lot of us in bands have been in these situations many times before in either putting a band together or auditioning replacement members.
Expectations are really high based on previous communications and when it comes to actually auditioning them (if it even gets that far), they have nowhere near the capabilities they have talked themselves up to have, reality soon hits and it’s a massive disappointment.
We know how you feel, keep at it, you may have a few more to weed through, but you will find someone suitable at some point.