There seems to be a bug with farmers getting stuck inside the wooden chapel. They have their status as “picking up resources” but they just stay inside the chapel for months at a time. In the screenshot one field didn’t get planted the whole season, and the neighboring one didn’t get harvested. It happens on the other fields as well.
(edit) I unstaffed the chapel and converted everyone to paganism. Now they don’t idle and get stuck inside the chapel anymore.