You added nutrient on already amended soil that would probably grow plants fine from seedling stage and 6 weeks onward. You need to think in terms of what's actually in the soil medium and monitor plant response. You only feed a plant who's asking for nutrients in veg(in soil). Let the plants talk to you, tell you what to do and listen carefully.
I think you begin in the wrong end if you start your growing journey with top dressings and amendments. Instead of giving the plants readily available nutrients in a controlled manner with actual measurable strength with EC and pH you instead have to calculate the time it takes for the nutrients to degrade by microbes before they become available for the plant to uptake. There's many variables to take in to consideration for a new grower. How to feed the microbes and multiply them and how to keep soil temperature optimal.
Not blindly force feeding the plants and burning them to bits. That poor plant is probably done for. Maybe a flush would remove some excess nutrients.
I hope you're not a victim of Mr. Canuck on YouTube? Trying to mix inert coir and hydro with organic top dressings, a complete recipe for disaster.