Not being able to edit NSTextField on NSPopover even though Editable behavior is set

Question

I have an application, which open popover with NSTextField. The text field is not editable. Behavior for text field is set to Editable. I still can

Answer 1

If anyone is still looking for an answer to this, I am working in Swift.

At the time where you wish the field to allow text entry, I have used myTextField.becomeFirstReponder()

To opt out; just use myTextField.resignFirstResponder()