How's your temperatures? With colder temperatures our way. The change could be a cause.

And not to cause any trouble. It is only my opinion. But I wouldn't want my animals ingesting ANY kind of substrate. Which is why I use newspaper. And feed in the tubs.

Try switching to newspaper if it doesn't bother you. And like said above; wait until the next feeding day to attempt to feed again.

Again this is just my opinion. Hope it helps