your soil is hot beginning to lockout nutrients, seedlings need no help from you for the first 4-5 weeks ...just water

whats the soil brand name, not that it matter ALL that much because most soils today have ferts pre added

you have MORE than enough nutes in the bagged soil you use, then you added more nitrogen from worm castings, additionally youve been giving them SUPERthrive

Id transplant to fresh soil & leave them alone , your killing them with kindness