Burn or Deficiency or?

Side note, when amending the plants and top dressing, add in a bit of worm castings or more soil on top of the layer it was just mixed into. this helps it stay moist and breakdown efficiently.

I use Gaia Green and like it a lot. I have reticently started introducing fulvic acids to help boost absorption of the nutrients as well as using bio boosters in the medium like bacteria and fungi to help break it all down. It has helped a lot. Ph going in is one thing PH in the medium is another. If you just top dressed it might need a bit of time to break down and feed the plant or just to even out in the medium. Like others I would suggest lowering PH down to 6-6.2 I also advice against any runoff when growing with amendments as if you are washing out all the work of the microbes and then the medium does not have any nutrients till they break down more. Other things with Gaia i found, it needs a Mg boost and is heavy in N so a good mix of 284 + 444 is needed. sometimes 75/25 or 50/50 ratio. I would give it a bit more time and fix your PH. if you down have any PH down like phosphoric acid go to a bulk store or anywhere that sells citric acid and use it. Perfect for this. vinegar also works i just don't like it as much. Good Luck!

My guess would be your slightly out of the ph range that it requires to use up the correct nutrition. Try lowering ph to 6.2. Make sure you get plenty of runoff and check it's ph. I can't see any nutrients listed but I take it your using some bloom nutes.

Leaves and steams suggest a nutrient lockout. Try to flush and restore... Good Luck 💪💪💪