Lack of supplements and such, due to lack of eating. Generally, feeding consists of throwing a few crickets and roaches in the enclosure, and then collecting the corpses once they've died of old age or starvation. Any supplements dusted on to them will fall/rub off within a day or two, so I wouldn't count on the frog having gotten any.

No, I don't use thermometers in the enclosure, however I have a temp gun I use for the other critters. Enclosure was 23C as of a few min ago. Humidity is a guess only at this point, as I dont have any spare hygrometers to move in to the enclosure. Another enclosure nearby sits at 50% is much larger and much less water, so I would guess add at least another 20 due to the smaller size and far greater amount of water.

Currently no place to hide for the frog while experimenting with this new setup, sides aren't covered. I'll see about figuring out what I can do to make some changes for that.

No, no water treatment being done for chloramines as those aren't used in my area. Chlorine is eliminated by having the water stand for a few days to off gas. Been doing the same thing with a saltwater aquarium for fish and corals for years, without issue.

The temperature being low is a surprise based on some care sheets ive read, however easily fixed. I'll run a heat bulb and see if a few degrees makes a difference in his behaviour. A heat bulb will of course dry things out, making locating a hydrometer a bit of a necessity.

Any other issues I should look at?

Any suggestions on enclosure setups that are minimalist? The less dirt, or anything that a roach can burrow into and hide in, the better, as they're one of the easier items I have on hand to feed with.