Some plants like a LOT of light, and some plants don't like as much. Ontop of that LEDs are powerful, I learnt that the hard way. I am using a 480w SF, and I turn the dial on to 20% from seedling until most of veg which is 100w. Around week 4-5 I turn it up to 30%, which is 140w. With your 650w light the math on it is 6.5w per percentage, so 30% = 195w of light which might be too much even at 38". Maybe try turning it down to 20% which would be 130w and see how they look tomorrow or even later on today.