Does my last photo look like nutrient burn? Thank ...

hey man, it looks like nute burn but it's not nute burn. it's various nutrient lock outs from PH fluctuations due to irregular or underwatering. I had the same thing happen, but yours looks bad, just water slightly more and make sure you wait until it's dry enough to water again, this should fix the plant in one or two weeks, enjoy !

If you have not given them any nutes and only 1 is affected I would flush it out with 5.8ph water until your run off is around 5.8,-6 just to eliminate any possibility that there is something in your mix burning her. After flushing I would feed with 1/3 strength your nutes or less. This is something I do when I'm just not sure what is going on. Do you have tds/ppm meter? Hope this helps! Good luck!

It made me think of light burn...i had a seedling that within the 1st day or so of being under higher light hours she got burnt tips on the two 1st true leaves like yours. I adjusted the lighting and the leaves didnt get better but no other leaves were affected. Typically seeds this yound wont get nute burn unless you're giving them nutes. Theyre more often discolored by lights, poor qatering practices, or having ph issues. Happy growing..give her time, dont give up on her.✌️

It's unlikely in a coco coir/perlite mix that you are over watering it's very very hard. How much nutrients are you giving them? You have a few true leaves now, so you definitely need nutes, just not much. Try mixing at 1/4 or even a 1/8 the recommended dose. Also doesn't mention anything about Ph of your water. Make sure you are PHing the water before watering. Most people say 5.8, i like it a little higher 5.9 or an even 6. Litmus ph paper is cheap, i think i even seen it at Walmart before. Get some and use it. Ph adjustments should be made after the nutrients are Mixed. Ph generally lowers after adding nutrients.

Did you give them nutrients? It's not listed in your grow. If you gave seedlings nutrients that would probably burn them, however I've seen growers do it and not burn them, just by giving a little bit. Your problem looks more like overwatering issue (which in turn will lock out nutrients and show deficiency). Your other pics show leaves droopy and turned down, and most pics the soil looks drenched. I've done it myself on one of my current grows.

Yes deff nut burn flush her really good and hold off on nuts for a few weeks be just fine looking good