Mysteriously, 1P 5.4.1 suddenly quit filling fields. Running Safari 9.0.2 on El Capitan 10.11.2. No system or software changes.
Unchecked Fill In Logins on 1P toolbar icon menu. Restarted 1P and rechecked Fill In Logins. Restarted Safari. Restarted computer. Deleted extension and reinstalled. No result.
I'd very much appreciate your recommendations.