Do you have softened water inside that you are using. That could cause some problems. Can you mix it with distilled or rainwater? I had to save rainwater over winter in my garage to water my indoor plants, all my taps deliver softened water.

Thanks for the reply,
I don’t have softened water. Just regular tap water. I let the water sit at least overnight so the chlorine evaporates. I’ve been growing for 6 years and never had this problem. I’m not sure what’s going on.

You say you used sterilized equipment. Did you use sterile soil? Could be a DIY sterilization, but many commercial container soils are pre-sterilized. One has to suspect some serious fungal infection though, frankly, that top picture really reminds me of herbicide damage.

Hi thanks for the reply,
I used Gurneys’ seed starting soil and ProMix potting soil. I was thinking the same thing about that top picture. Maybe I should spray with serenade?

Somewhat sadly, fungicides are mostly preventative. They don't kill fungus once it is established. Gurney's First Start™ Seed Starter is sterile. The ProMix stuff is peat-based, and I think it is intentionally not sterilized, but pretty certain not to be fungally infected. So I suspect that's not the problem. The fact that you have some experience doing seed starting makes this especially strange. I assume that you've kept control of the temperatures. 5 week old seedlings need fertilization. What have you used?

Could it be leaf roll and damage from hot lights or overly dry conditions?

The potting soil has light fertilizer. I also mixed in worm castings and lightly Jobes organic seed starter fertilizer. I keep the dirt moist. Checked with a moisture meter. Always watered from the bottom tray. I have a seed heat mat and a small fan for light breeze. The fan is on several times a week off at night. Heat mat it off at night. The grow light is an intense one but I’ve used it the past 3-4 years. I’m at a loss. I’ll separate the affected plants to control spread.

I'm thinking you over fertilized your plants. I did it one year, used way to much liquid miracle grow in my water and had similar problems so I tried to leach the fertilizer out of the soil over and over and over. Lost 1/2 my peppers and a third of my tomatoes if I remember correctly. Don't take my word for it, watch this You tube video of a guy intentionally over fertilizing plants and showing the results. See if your plants are the same, I think they are.

https://www.youtube.com/watch?v=8Hv_u-PA60Q

Thanks. I will give it a look. Maybe I should repot them without the added worm dirt and fertilizer.

I will not use the fan anymore and maybe raise the lights?

Those lights are powerful, and should be at least a few inches above the foliage. The fan is pretty irrelevant. Overfertilization is a possibility. That's why I was asking about fertilizer. That Jobes stuff has feather meal which, while allegedly slow release, packs a pretty strong nitrogen punch.

Ok thanks. The lights are kept over a foot away from the foliage. I’ll try to repot the affected plants and hope the rest stay strong. I appreciate all of the help.