Trying to use TextAlignment->Center in Text in Graphics3D pushes text far off of background

I am trying to annotate a plot with text. The text is intentionally line wrapped, and I want it to be centered, so I am trying to use TextAlignment. However, when I do this, the text gets pushed way off of the location in the plot where it is supposed to appear.

A MWE is:

Show[
Graphics3D[Sphere[{-1,1.5,1}]],
Graphics3D[Sphere[{1,1.5,1}]],
Graphics3D[Text[Style["THIS IS TEST\nTEXT",Medium,Bold,TextAlignment->Center],{-1,1.5,1},{0,0},Background->Green]]
]


This shows that the text has been moved far off of its background (although it is properly centering the two lines of text relative to one another, as desired).

How can I fix this?