The “droop” is because the plants have reached their DLI capacity and as mentioned are anticipating the upcoming lights-out.
That leaf curl edge, IMO it’s one of a few things:
- leaf surface temp (NOT room temp) is higher than the plant likes
- something funky going on in the root system, like too many dead/dying root tips for various reasons
- humidity is lower than the plant likes
- literally some plants just do that, no matter what
