Here is a code example
spherePlot = Graphics3D[{
RGBColor[0, 0.74, 0.91], Opacity[0.7], Sphere[{0, 0, 0}, 0.998]
}];
labelPlot = Graphics3D[
Style[{
Text["A", {Cos[60 \[Degree]], 0, Sin[60 \[Degree]]}],
Text["B", {Cos[45 \[Degree]], Sin[-45 \[Degree]], 0}]
}, "Panel", 20, Background -> None
]
];
Show[
spherePlot,
labelPlot,
Boxed -> False
]
Comparision (dont have 11.0.1 installed anymore):
In[4]:= $Version
Out[4]= "10.4.1 for Microsoft Windows (64-bit) (April 11, 2016)"
In[1]:= $Version
Out[1]= "11.1.0 for Microsoft Windows (64-bit) (March 13, 2017)"
Edit: If the Opacity directive is removed, or set to 1, the labels renders as expected
