@soraiataipa
On the Items property of your Person DropDown are you using office365users? Like below
Filter(Office365Users.SearchUser({searchTerm:Person.SearchText}))
and on the Update Property of the Data Card use below
If(!IsBlank(personControl.Selected.Mail)&&!IsEmpty(personControl.Selected.Mail),{'@odata.type': "#Microsoft.Azure.Connectors.SharePoint.SPListExpandedUser",
Claims:"i:0#.f|membership|" & Lower(projectplanmanager.Selected.Mail),
Department:"",
DisplayName:personControl.Selected.DisplayName,
Email:personControl.Selected.Mail,
JobTitle:".",
Picture:"."},{'@odata.type': "#Microsoft.Azure.Connectors.SharePoint.SPListExpandedUser",
Claims:"i:0#.f|membership|" & Lower(ThisItem.PersonfieldInsharepoint.Email),
Department:"",
DisplayName:ThisItem.PersonfieldInsharepoint.DisplayName,
Email:ThisItem.PersonfieldInsharepoint.Email,
JobTitle:".",
Picture:"."})