Underwatering issue or? Please help

Woke up this morning to two of my plants looking like this. Rest we're fine. All on the same watering schedule/feed. I suspect underwatering but I want to be sure. Just happened so fast. Any help or second opinions would be much appreciated. Thank you all!

Can’t tell from the pictures, are those leaves dead? It doesn’t look like classic lack of water, it almost looks like a light/heat stress, PH issue, or over fertilizing, but if they are all getting the same food and water I can’t explain it. It really looks like heat stress, if you’re lights are on at night, make sure your fan timer is cycling correctly.

I can try to get some more soon, and it seems like it, but some leaves aren't drooping at all, just twisting and becoming dry, starting with the tips, but barely any "bad" discoloration. I raised the light some, and I'm about to start the flushing process so I can try to balance any issues with PH or fert. No, they come on at 7am off at 7pm. Thank you so much for the feedback, every bit helps!

Usually when leaves turn that fast, and there’s no discoloration it’s a heat/light issue, best of luck! The buds looks very nice.

If it was under watered, the branches and stems would be drooping. You get wilted leaves that look like wet spinach, not dried out crunchy leaves (at least not overnight).

so, not sure the issue, but not a short term lack of water issue imo.

Water the plant!

Yeah I raised my light about 6 inches and I'll start flushing here soon, hoping to push through to week 8. I've narrowed it down to light or PH/Nute issue. Someone on another forum suggested some sort of root shock. So I'm hoping less intense light/flushing will allow them to finish nicely.

Also, thank you guys!

It looks like you let it dry out at some point
It comes back to bite you weeks later not immediately
No idea why you would flush

Looking at the pic, it doesn't look like nutes. A few burnt tips, but nothing drastic. My guess, from the tacoing, is heat or light. What's the temps, and what light are you using, and at what height? Do you have any more pics?

Are you in soil or coco?