Seedling bleched at 3rd node, deformed leaf

That's light stress. I have a 100 watt led from Spider Farmer and it's set at 75% and 24" away from the plant at this stage in her life. With these new LED lights that are full spectrum, she could be sitting right under a specific diode she doesn't like. If power and distance are fine then try moving her. These leaves won't recover so watch new growth.

From my experience, it's usually light stress, especially if you're using strong LEDs and they’re too close. I’d try raising the light or dimming it a bit. Also worth checking if you're feeding too early — seedlings don’t need nutes yet if you're in decent soil. pH can play a role, too, so make sure it's in the right range. Temps and humidity matter a lot at this stage, too. I just thought I’d share it in case it helps!

I have not experienced it, but it looks like iron deficiency. Not enough iron in what you're using (doubtful as its a micronutient so it doesnt need much), or something blocking it would be my guess since there's no info on these. I'd check what I'm using and compare to Mulders Chart to see if something is blocking it, provided ph and ec are ok. Also I have had some seeds from RQS that grew weird too. More finicky than others. Again just my guess on it. Best of Luck! Happy Growing!