I think gliders natural instincts is to be very jumpy. After all in the wild they are just a moment away from being dinner for a snake or a bird. One of the reasons they only live 5 to 6 years in the wild.
We have one female that is very sweet and bonded and nice, after we hold her for awhile and put her back in cage, she will sit there frozen in the same spot sometimes for 20 minutes before she goes back to pouch or moves at all.
we had a female in a cage by herself for awhile, she would run on the wheel then sit in the bottom and look around, run some then sit for 10 minutes or more just looking around the room.
some of our gliders don't like the bonding pouch, think if I put more then one in it she would do better.
We have Gus, who will be on my shoulder or arms but is CONSTANTLY looking around for a place to jump and go off and explore, he is super friendly NEVER BITES, but unlike sophie and gizmo who will stay with us during the day, he will day or night want to run around and explore.
If your glider is a healthy weight and eats good, the vet says he's fine then I think your probably ok.