glass panic.
Is there something he is reaching for on the other side of the glass? I had to move all my light cords because mine was trying to climb them through the glass and if I didn't notice the light cords it would have looked exactly like what you described.
young and old chams alike can have an issue with glass, as previously observed they often try to climb on stuff outside the glass, imo, chams dont understand the glass issue very well, imo, its important to have their cage set up in a way that encourages them to not want to stray from their territory.
the neonates in my public album were in a 10 g aq, i dont know if you can see it in any of the pictures but i had bamboo skewers running from all 4 corners up to the top of the pots, if there is not a branch there to distract them they can lose sense of direction and just stress and glass panic. but imo, if there is a branch right in the immediate vicinity they will usually grab it in short order. but if they are focused on the outside of the glass, they are not that good at figuring out there is a branch 2or3" away.
have you ever noticed that chams sometimes seem to paw at a branch without looking. its important to remember that because chams have their eyes on the side of their head, that they have different visual perception than forward looking animals. they can look forward when they need to focus on something, but in their mind, the only reason to do that would be feeding.
imo they would rather grab the branch if they realize its there. i think if you put lots of little (preferably squiggly) type branches in the areas where it tends to glass stress the most, that it will probably help. im not saying it will fix it all together but i think overall your cham will spend less time stressing over the glass if there is an over abundence of branches in those areas. imo, they usually get over it after a while or in some cases as they get older, so you just got to find ways to distract them during that period, for instance if they tend to do it at the same time of day, you might consider making that your feeding time.
plus, imo, making his cage setup in such a way that it is the place he would rather be couldnt hurt either.
imo, if you are unable to solve the problem and it is still doing it weeks down the road. you might want to consider switching to a screen cage because crawling is better than stressing. if it is stressing on any continuous basis. then it is paying a health price for it.
also, oversupplementation can make chams edgy, so, imo, it might be worth your while to take a closer look at your supp regimen. just my 2c worth jmo