If you can post a pic of the enclosure that could help. If your frogs are digging they are either (since newly acquired) trying to hide or the humidity is to low.

Basically, you need to ensure that tank is humid and temp are about 68 to 70 at night and 72 to 78 during the day time.
All while keeping the humidity above 60 percent but not higher than probably 75 percent.

So, do you have a screen top? If so you probably need to cover 1/2 to 2/3 of the top with either a piece of glass or plexi glass or plastic to stop the humidity and heat from escaping. I would move the heat pad to a side and not underneath.

Your frogs are tree frogs so they usually don't spend any time on the substrate and should be hanging out in trees. So, providing plants branches, vines and accents they can climb on, hide behind, sleep on, and use for traveling about the tank is a must.

I would 1st get the humidity up and monitor the temps, while also giving them something to climb on.

You can also feed the crickets in a glass cereal bowl so the crickets don't roam the tank and you can monitor eating.
Sink the bowl slightly into the substrate and they will find them.