My fat boy doesn't glide, even if I encourage him to (from my arm to the couch). He'll climb down my body every time lol. He runs on the wheel exactly as you described! His sister, who is also a bit chunky, will glide. I got them at the same exact time.
My vision impaired glider runs and leaps like bonkers on the wheel. I think it's a total blast for her! She tries to leap and glide a bit while we play, too. Usually just from a low object to me.
So...who knows! Maybe he just doesn't want to.