Okay this is all good info.
I've had him for exactly 8 days.
Right now he's in a screen cage, 18x18x36 with 2 pothos plants, and a couple fake ones to fill it in while the plants grow. I DO need to swap out his horizontal "sticks" - they're tape-wrapped dowel rods with some bendable fake vines (not the mossy type ones at last) (I inherited both of those things, and the cage itself from a chameleon owner whose cham passed away a number of months ago) and while I wiped it down when I got it used, perhaps that was an issue with the previous cham and I didn't clean well enough? Either way, it's a current issue that I clearly need to handle.
Roger roger on the "don't move cage stuff now," assuming he'll potentially spread the coccidia around while he's being treated.
Good to hear the dubias are proooobably safe. I got the crickets from a local pet shop here. Possible they had it too I suppose. I'm not sure how long it takes for it to move/show up.
Spot-cleaning will become much simpler once I do a deep clean, I imagine too. I'll definitely be getting on that asap.