Hey there, so going just off this 1 week of info the 1st thing that came to.my mind was perhaps a little light stress from having the 400 watt led when they're young..especially a high powered light that's on 24 hours and less than 24 inches away.
There could be many other things as well like high nutrient soil(are you using a specific brand?). Otherwise perhaps they're experiencing some watering irritation either from the decent size pots or an over/under watering?
If you're leaning towards thrips or another invader, perhaps pick up a few of those yellow sticky card traps and put them at soil level in each pot and see if they catch anything.
Hopefully it's just a temporary problem and they'll just grow out of it soon, but just a couple possibilities of what might cause some issues.
Happy growing to you โ๏ธ