Hi all! I've had these two hoyas for a couple of months under grow lights near a window and they've been happily growing, but recently I'm having issues and I'm not sure whether I've got pests or maybe I overwatered? I'm not quite used to the substrate they came in.

The lady I got them from said she waters once a week, but I read that if a baby leaf shrivels up, it might be for lack of water, so I upped it to twice. They're sitting shoulder to shoulder, though, so if they have mites I can't see, they could easily have spread. I watered them and went away for 2 nights- they don't look great. The new leaf on the sumatra caudata looked a little floppy previously, but I thought maybe because it was new, or maybe it was too close to the light since it's been growing straight up. The petiole looks a bit brown, and the older ones don't. What do you think?

The window light is N/W I think, but we've a balcony, so the light is very indirect, but the grow lights are 9 hours per day. Occasionally I mist with orchid spray. Also I don't currently have a systemic in either of these. I did brush aside some soil in the sunrise, and the roots looked quite lush. The sumatra is more difficult since the mix is super chunky, so I didn't look.