Summary: I orederd a pair of JH 16Pro IEMs in May. It is now June 15th. Since ordering the first pair, I have returned at my cost of $21.15 each time, the IEMs three times. Each time, Caleb Ellis, who manages the department that makes the IEMs, said he could not explain what had happened.
The left IEM of the first pair fitted perfectly with the impressions I paid an audiologist $100 to make and send to JH Audio in Florida. The right one was painful.