Is this normal?

[DVirginiana]

Something is causing this; to help us figure out what you'll need to answer the Trouble in the Enclosure questions that have already been posted. There's a good chance you may need to see a vet.

Are you treating the water you expand the substrate and fill the water dish with (like you would for a fishtank)? If you haven't been, you'll need to change the substrate for some that is expanded with treated water. Use treated water for soaking too; if you don't it'll just exacerbate the problem.
But you can try a soak in lukewarm treated water with a few drops of honey stirred in (no deeper than the frog's chin level).

[MrsNoah]

Thank you, DVirginiana!
I have never treated his water. I let it sit out for 24 hours before putting it in his bowl. He spends most of his time buried in the substrate. He only comes out to eat and soak once a week or so.
I will keep watching him!

Lisa