One question is the glass clear.
I have had this problem with my whites tree frogs.
They were perplexed that they could see the crickets moving in side the bowl but couldn't
eat them though the glass. They kept head butting the glass and tongue striking the bowl.

So I buried the bowl into the substrate so the lip edge of the bowl is almost flush with the
substrate.
And let the feast commence.'

And I also found out that using a white bowl that contrasts better with the feeders makes the frogs
find the feeders easier.

Hope this helps.