This might be cultivar specific as my 3bog took off and had no issues till day 30 running at 25g/gal.I'm a few weeks in my grow and it look days old. Too much Nitrogen for sure. I'm thinking a top layer of lighter mix soil with no dots might help this problem if anyone else tries em again. Or fill around a 30 ounce cup and then fill the cup hole with a light mix soil so the dots don't burn young plants. I didnt have this problem my first run.
Oddly enough my 20g/gal Ogreberry is on day 33 and showing no problems at all yet so fingers crossed