So you're only feeding him waxworms as of now in his diet? That's not good even though you only feed him one every couple of days. Sorry if I misunderstood, maybe you can clarify.

The log hide; take it out and rinse down with soap and water, let it dry out, put it back in. It could be harboring mold in moist-wet conditions if the log is soaked. Try to keep it dry for the most part.

At least you got him eating, just try to keep him on a healthy diet. Thanks for updating.