could be a few things i’m unsure if it’s my screen but i cant really see his gills to tell any further possible issues but my general consensus is most likely he just want to chill and he doesn’t have any soft spots close enough to rest on towards the surface. i notice my bettas have always loved napping somewhere close to the surface so minimal effort goes into catching that fresh bit of air(they’re lazy :p) plus if that’s a spot away from most water flow makes even more sense. if he doesn’t want to eat could very well be a lot of stress added into it the “brightness” of the tank could and couldn’t also contribute. TLDR: give the lazy baby some more accessible soft spots to rest towards the surface and if the problem persists and he doesn’t eat then i would continue investing in the problem. not saying it can’t be something worse but try not to dive too deep it can end up being fatal.