Hi,
With regard to not being able to climb the glass, this can be due to a few reasons, the main ones being stuck shed or poor diet. Can you describe their enclosure in best detail as possible including temperature?
You are going to have to provide them with a more diverse diet. You can try flightless fruitflies, springtails, tropical woodlice, flightless flies, firebrats, field sweepings and so on. On days where you provide food other than crickets you should dust with a normal all in one vitamin supplement. On days where you provide crickets dust with a phosphorus free calcium. Never mix the two supplements!
If they are adults (10-12 months) feeding them 2-3 times a week is fine, the third feeding should be your cricket calcium day. If they are younger you will want to feed them every other day with the same 3rd day rule.
What I do is give my adult geckos Frutiflies or Flightless flies (depending on their size) on Monday. Wednesday is Repashy day, Friday is cricket day with calcium.
Replace your fruit with Repashy Gecko MRP. It will take a bit to get them to like it and you may have to add some regular fruit the first few times, but eventually they will take it with welcome mouths by itself. Peach or Passionfruit flavor is a top hit with day geckos.
You can order Repashy Gecko MRP through
Gecko Ranch - Supplies, Breeds, Herpetology
Repashy is great stuff and you never have to worry about adding anything extra to it supplement wise.
You will also want to leave a dish with crushed up cuttlefish bone at all times in the vivarium. This should be changed out once a week.
Now back to stuck shed (which can also be caused by poor diet btw). If your geckos have stuck shed, it could well be the temperatures in your enclosure are not right also, either they are too low or too high. So it is very important for you to list these.