Li Shenron
Legend
An immobile, faintly shimmering magical sphere surrounds you and excludes all spell effects of 3rd level or lower.
...
You can leave and return to the globe without penalty.
I have always played it that the globe always remains centered on you and moves with you... does the above mean that instead the globe is centered on you when you cast it but it remains in place and if you move you actually move out of it?