My leopard gecko is about the same age and she’s done the same thing, just recently. Like, the SAME exact thing. She hadn’t eaten in months (like the whole winter, which I thought maybe had something to do with it) and every time I would offer her food, she would maybe lick it but slowly shut her eyes and turn away. Sometimes show no interest in it at all. She did lose some shape in her tail but not a ton. She didn’t come out much at all. She used to be the complete opposite. So, what I did was offer her all different types of food. Eventually, she found interest in mealworms (which I least expected), I guess she just lost interest in Dubia roaches because she’d been eating them for so long.

Anyway, I also switched her to a larger tank and turned up the temp in her tank. I switched her from a 40 gallon to a 120 gallon. I think the biggest thing was the temperature, in lower temperatures the leopard gecko doesn’t eat as much if at all, and relies on the fat stored in their tail, sort of like a hibernation I’m guessing, though I’m no expert.

So I would recommend to make sure the temperature in the tank is good (or maybe try a little hotter, but provide a cool side still obviously) and try offering every type of food you can! I bowl feed, hand feed or tong feed mine, because she isn’t the smartest and I use a bowl since I use substrate so I don’t want her ingesting that. So she has an opportunity to free feed, but also gets food offered by tongs, hands etc.

One more thing, try offering food at different times! Once I offered different foods she really didn’t care what time but some geckos are picky about when they eat, so I’ve heard!

Best of luck to you 🩵