Probably not from light, but it should be mostly light-proof to prevent algae and rot. I've had some take over two weeks to root, but if you're seeing the bumps just be patient, roots should follow soon. Higher temperatures mean faster rooting and higher chance of mold or rot. Lower temps mean safer conditions and slower rooting. Without re-reading everything, you didn't take cuttings during flower did you? These are much harder to root.