It could be that your humi still needs more time to season. Have you checked it to make sure it seals well? An easy way to do this is to put a small flashlight inside and see if you can see any light coming thru the cracks. If the humi doesn't seal well, it will never hold the rh you want. If it was a brand new wooden humi, I wouldn't be surprised if it just needed more time. Give it at least another week before you panic!