U might be on to something here. I did notice some of the tips curling inwards which seems to be nitrogen toxicity, if this is true then my 780ppm nutrient level might be a little too hot for them. Since you noticed similar spots and fixed it by lowering your dose, i will be doing the same and see if this stops the issue.
Its my 1st time growing gelato 33 and looks like this is a very demanding strain ( previously i did mac and loui 13 and never had issues even when hitting 1200 ppm)
I did add a little bit of Epsom salt yesterday since the stems are purple . ill update here when i get some news.