It may well be the 40 breeder. That's a pretty large glass tank so a few issues may have arisen. First will be the fact that these snakes tend to not do well in large, open tanks where they feel exposed. Remember these snakes naturally live a lot of their lives underground tucked into dark burrows and tunnels so big, open bright areas tend to freak them out.
Then there's the issue of keeping a 40 breeder with a large, open mesh lid at the right temps and humidity (unless you've already dealt with that).
What did you have this snake in before you moved it to the 40 breeder?