I think you are getting some light burn. I had 2 of my colas get too close last run, so I was able to clearly see what happened from them getting too close.
I need to keep them about a forearm's length away. Any closer and the tops start to bleach a little, the pistils will start to recede, and funky leaf growth starts happening. The buds ended up growing in a funky bunch. They also did not frost up like the rest of the plant. All the other colas were probably the frostiest I've ever run. I knew temps were good, so it was definitely getting too close to the light that messed up those couple buds.
You will shave years off of your learning curve from some of the growers on this site. I wish i would have come to one of these forums when i first started growing. Would have saved a lot of time and frustration. Shit i am a novice compared to a lot of these growers on here. Seems like i learn something new every day on here but i do not mind sharing what i do know.
I think my big lesson was RH. In the beginning I never really worried about it. Long story short, I added humidity control to my grow, and I could see the growth difference. Wished I had done it long before I finally did.
Capt's post sums it for me too. I'm a 10 year novice compared to some of these guys, but have learned a bit on the journey, lol.