though there’s a significant difference in height among the plants, and the last pic shows a much lower plant also exhibiting the same symptoms. this leads me to believe it’s not about the light
Hopefully someone with more experience will chime in on this but they looking a bit crispy. If you raised the light after this started, let it go a few days and see how they look.
My first thoughts looking at the picture you are wetting the plant and putting it under the light the water acting as a magnifier you’re burning the top of the plants . Let’s see what other community members think.
Yeah, stop spraying your plants. Raising the light helped too. But stop spraying them. Spraying should only be done if they don’t have roots. Clones and seedlings. There’s not reason to spray them otherwise.
The single leaf at the bottom normally dies and falls off don’t worry about it. Over all your plants look good. Also see powdery look on the leafs at the bottom I’m assuming that’s what you been spraying it with.