A few things stand out in your set up that could be a factor. This is a long post, but if you read it and have more questions, just ask
1st - the substrate is a hotly debated topic, most keepers recommend only using loose substrate as egg-box material for gravid females. I personally use a mix of slate tile, repti-carpet, and natural large rocks. I tried using eco-earth as my moist hide substrate but my male kept eating it. My female did fine with it in her egg box while she was going through that. Until you know what is causing the lack of eating I'd switch to something solid that she can't eat on accident.
2nd - Depending on the wattage of the basking light, it might be higher than 80*. Are your thermometers the digital kind, one that measures the hot side and one that measures the cool. If she is always on the cool side, my guess would be that the other side is too hot. You can get a thermal temp gun for $15 on amazon that will allow you to check the surface temps of everything, the digital thermometers only measure air temp.
Temperatures - A temperature gradient from warm to cool maintains your leo's health. Here's a temperature guide for all leopard geckos as measured with the probe of a digital thermometer or a temp gun. Set your thermostat at 91*F/32.8*C.
All Heat sources need to be on a thermostat - esp heat mats and CHE's, dimmers can work in a pinch for red bulbs
I use hot glue to fix the thermostat's probe and a digital thermometer's probe together, but offset a little (gluing the wires not the probe heads themselves). Place them right on top of the substrate underneath the warm dry hide. If you use a UTH + a CHE you'll need 2 separate thermostats, because ground and air temperatures are substantially different.
Warm dry hide ground temperature: 88-92 F (31.1-33.3 C) inside a leo's warm dry hide.
Warm humid/moist hide: Place the humid hide 100% on top of the heat mat (or under the heat light / CHE). Keep temperatures similar to the warm dry hide.
Cool dry hide ground temperature: 70ish-75 F (21.1-23.9 C) Usually the cool end ground temperature matches the room temperature where the enclosure sits.
no greater than 82ish F (27.8ish C) surface temperature - 4 inches (10 cm) above ground on the warm end
no greater than 75 F (23.9 C) surface temperature - 4 inches (10 cm) above ground on the cool end
Leave your heat mat on 24/7 IF ambient room temperatures drop lower than 67ish*F (19.4*C). If NOT, during the night turn off overhead lighting/heating (~12 hours on and ~12 hours off).
Elevate your entire enclosure 1/4 inch to 1/2 inch off the stand to prevent house fires!!! For larger enclosures elevate the enclosure at each corner and at center edges! Use sticky chair pads, Pink Pearl erasers, sturdy bottle caps, small tiles, or wooden blocks. Wrought iron stands support the periphery of the tank, but are completely open on the bottom.
3) If your tank is too hot - she is likely also dehydrated. A moist hide will help with this. You can use damp paper towels, sphagnum moss, or chemical free natural sponges. Also a 10-15 min bath in warm (no more than 85*) chlorine free water twice a week if she's having any trouble with stools or has eaten substrate - leo's can't swim well, the water only need to be deep enough for her belly to sit in it.
4) Unless you have a thermostat, don't use the heat mat - these will quickly get to 120+ which can cook her
5) I'm not familiar with the flukers brand vitamins, but she needs a plain calcium supplement, a calcium with D3 supplement, and a multivitamin that does not have D3 and has retinol as the vit A source (not beta carotene). Even with a UVB light she should get a calcium supplement with D3 twice a month just in case she is not utilizing the light. A lack of either D3 or retinol can cause them to be lethargic / have a poor appetite.
example:
Weekly Schedule 126 for Leopard Geckos 18+ months old (withOUT UVB)
The medical term for Metabolic Bone Disease = Nutritional Secondary HyperParathyroidism. NSHP symptoms include leaning to one side when walking, walking on one or both "elbows", bowed limbs, belly dragging, and an underbite. Difficulty chewing should be closely monitored.
Monday > > crickets or dubia lightly dusted with Zoo Med's Repti Calcium with D3
Thursday > > crickets or dubia lightly dusted with Zoo Med's ReptiVite multivitamins withOUT D3
Saturday > > Optional: mealworms, superworms, or black soldier fly larvae (Phoenix worms) > > no dusting
If you are using UVB lights - then you would do plain calcium twice a month, and calcium with D3 twice a month - alternating weeks.
7) you should also be gut feeding her bugs for 24-48 hours before feeding them to her. When mealworms are kept in the fridge the use their own bodies as a source of energy which makes them more like potato chips than real food once she get to them. Kale, collard greens, sweet potato, and other veggies are great for the bugs. You can even buy or make dry powder-like foods for them. Dubia roaches are one of the better feeders as far as nutrition goes, crickets are not great and tend to carry parasites, and things like wax worms should be just for treats. (I have to give wax worms to mine once a week as it is the only thing they will eat their vitamins on).
Hope this helps some - I know it is a lot, but reptiles are very sensitive to change even though they are hardy as far as staying alive. It just takes some tinkering to get them to thrive.
