It is working fine for me, can you give more information ?
What happened or what did you do before you entered it, while you are in the sphere and after you exit the sphere ?
If it happens again, also tell me what it shows in /checkimmunity cmd
Edit (24/7): I've found the cause, you probably used /heal in the sphere. I've pushed a temporary fix which is by disallowing the use of heal in the sphere. I will fix the script that handles sphere tomorrow..
Edit (25/7): Fixed, let me know if it's still happening..