Crested gecko weight loss - concerning?

[lil_bissy]

So I have had my male crested gecko for over 7 years now. He has always been quite small and has never really had a raging appetite, especially in the winter. This summer, I kept feeding him as I usually do and his appetite randomly skyrocketed. However, now that it is the winter, it's hard to tell if he is really eating at all. He has lost 6 grams, which feels aggressive, but he had recently put on about 11g with his appetite increase.

In terms of husbandry, I have a ceramic heat emitter and thermostat (I live in Canada and my room is on the corner of the house) to keep the temperature near the top of the cage at about 75F or a bit warmer. There are also cooler areas available to him. I mist twice a day since winters in Alberta are so dry and to offset the drying of the heat emitter. I have offered his food in different locations of his cage and tried different types of Repashy as well as Zoomed's newer formulas.

Weight history:

Date	Weight (g)
Sept. 10, 2014	31
Sept. 24, 2014	35
Oct. 11, 2014	38
Oct. 22, 2014	37
Nov. 19, 2014	37
Mar. 15, 2015	33
Aug. 12, 2015	38
Oct. 9, 2016	37
Feb. 27, 2018	38
Apr. 16, 2018	38
Jul. 11, 2018	37
Apr. 3, 2019	33
Jul. 3, 2019	33
Oct. 21, 2019	36
Aug. 25, 2020	37
Dec. 14, 2020	36
Aug. 2, 2021	42
Oct. 12, 2021	53
Dec. 14, 2021	47

Pictures:
https://ball-pythons.net/gallery//sh...mageuser=73209
https://ball-pythons.net/gallery//sh...mageuser=73209
https://ball-pythons.net/gallery//sh...mageuser=73209
https://ball-pythons.net/gallery//sh...mageuser=73209