In order to read the contact person's email change history, you need to pass the RELATION UUID, not the account UUID or contact UUIDvar contactParty = this.MainContactParty;if (contactParty.IsSet()) {var contactID = contactParty.PartyID.RemoveLeading...

we found a workaround:

rohit.singh check my prev. comment, there is a pic - https://imgur.com/a/e0hsTKg

re-uploaded screenshots to imgurhttps://imgur.com/a/e0hsTKg