I would start by making sure is was dark at night and light in the day time, add an extra light in the room during daytime if its not very light.
If your gliders are new, it could be them getting used to the new place.
when we started with gliders, we put them in my bedroom during daytime, very dark as I would sleep for night work, they would be away from dogs. but I found them awake and running around cage on wheel at 3pm!!