Old ST1R
Grow Yer Own Stone
The light burn sounds more likely. They are under a Spider Farmer 100w Quantum board and they might have been too or grew too close at one point.Light burn, did you change lights a week earlier or lower the lights? The newer growth is adjusted to your current setup, but the lower leaves reacted to the change. These guys like higher humidity (50%+) and can also react adversely to changes in humidity as a warning.
I stopped trying to control the humidity a few grows ago. Just not worth it IMO. Right now, we’re about 34% and dropping as the temperature drops outside.