Hi. Your uvb is a bit too far away for your guy to be getting optimal levels. It should be around 20 cm between basking branch and uvb. I understand and appreciate why you have one end of the uvb elevated, but I would keep it flat on top of the enclosure and by having the basking branches at different levels, he can choose his exposure that way. Also, when did you last change your uvb bulb? While I believe you’re using the Arcadia supplement trio correctly, I am wondering if he is getting adequate amounts of it. I’m guessing you’re feeding large crickets. I suggest giving him more of a variety of feeders that have been well cared for to provide maximum nutrition. Instead of giving just one large feeder daily, try giving him 3-4 med to med/lg feeders (or equivalent) either every other day or 3 days a week (plus one treat day). Besides it giving him a bit more enrichment and enjoyment (for lack of a better word) while eating, he’ll have more bugs to transfer nutrition and the supplements to him.
While not really related to his tongue issue, he does definitely need a larger enclosure. The minimum size he should be in is 90x90x120 cm and if you can go even larger than that, he will use all of the space. This is what I do and encourage others to do if they are able.
https://chameleonacademy.com/double-wide-chameleon-cage-project/ With larger space, you can provide better gradients of temperature and humidity, more live plants to increase his humidity up to the ideal 50-70% range during the day and lots more branches and vines for him to travel all over on. Since you’re using metric measurement, I assume you aren’t in the US, so unfortunately aren’t able to get these shipped to you if you switch to a screened enclosure.
https://dragonstrand.com/dragon-ledges/ Several members have made their own versions using sheet metal or wood. I’m not that handy and had to use scrap garden trellis when I didn’t have time to order some Dragon Ledges. It’s worked so well, that I’ve bought a panel and am using it to set up new enclosures. However you do it, you need to make sure that the frame bears the weight.
Returning to your guy’s tongue, are you sure of his age? I’m finding with my oldest chameleon (5 yrs old) that she has stopped shooting her tongue far and gets close to her food before then grabbing it with her tongue. I don’t see a feeding station in the enclosure. Adding one will help ensure that he is able to catch his food. Definitely never use tongs to offer food. There’s always the risk that we can’t release as quick as they grab and their tongue can get pulled (like a muscle injury). Some chameleons have had such severe injury from just one time that they ended up losing their entire tongue.
I hope I’ve been of some help.
