Help! I just started to flower my plants and one collapsed!

First time grower. I decided it was time to start to flower these two and swapped my 6500 for 2700s. The one on the right seems ok, but the one on the left collapsed in like an hour. I watered them yesterday, so I know it didn't happen just like that to over watering. What could it be?

Looks weak. Over watering?

over watered . repot it . put in a mix of 50/50 perlite to get ride of this issue later and possible root rot . so yes carefully take it out of the pot . and gently nock off the dirt off the roots. it does not have to be all of the dirt. if it feels like it will break the roots then stop. just repot it into a bigger pot with this perlite .

Ok, in the time I wrote this, she perked back up. I had let it get hot in the closet (Temp read 99F at top) as I was trying to gauge how much ventilation I needed for these new bulbs. Now that I have more ventilation, temp is down to 83F. Could that have been what caused her to sag?

But regardless, I should switch them into larger pots with a 50/50 mix?

Definitely the temps. Even 83 is right on the threshold. Once it gets to 85 it becomes a problem. It transpired to quickly.

im still going with my water story. a plant out side in the sun gets up to 110 or 120 out side here in Michigan . with no issues . and your other plants were ok . my room goes up to 110 in the summer here a few times insanely or not that sounds . and they look ok. inside a barn .