Could be. Not having a proper dark to light ratio could make them more agitated, and gives them hours of sitting in a coop with nothing to do. Why do you run a light for so long?I here that, but again...It's been that way for over a year and a half and this is kind of a sudden onset of symptoms...Are you suggesting it's pecking from too much light???
Could you share some pictures of them in their current state? I have had lots of hard molting birds this year, more than I usually see. They don't always molt the same from year to year. Extra lighting can cause goofy molts too.