I have same issue. I'm calcularing final text in shouldChangeCharactersIn. For example, current text is "1234". I enter "5" in text field. Result text after first call of shouldChangeCharactersIn is "12345". Result text after second call of shouldChangeCharactersIn is "1234". And one more thing. Notification "textDidChangeNotification" is sent correctly. Only once with final text is "12345".

Sorry. Issue was on our server side.