It happens. I wouldn’t worry too much about it unless a lot of the leaves are turning yellow. I have some of that on my autos, they are budding up nice. I adjusted the pH and checked the nutrients in the run off. I was over doing it a bit. Didn’t hurt in the long run.
To much first you should have started with Foxfarm Happy frog then at flowering stage switch to ocean starting off they don’t need so many nutrients so your soil is considered “TO HOT” just my opinion but that’s why I personally think you’re getting that burn. How’s your pH level’s?
I also had 2 separate pH issues, to much alkaline constant 8.0 twice first time brewed a pot of coffee and mixed one cup of 300mls to 1 Gallon of water, or 1Tblsp white distilled vinegar to 1 Gallon of water worked twice for me if you’re having a pH issue…