Comment 2 for bug 819278

I have seen the same problem.
As driver ver. 8.593-100 seemed to show up the case, I tried a workaround.

Old driver (not from amd site - amd legacy drivers has got the same 8.593 driver indifferent from Catalyst version)
  installed: Catalyst 8.12 driver ver.: 8.561
                        Openglx showed: OpenGL 2.0 support.
                                Problem disappeared from Stellarium.
                                fps.: 70 to 120

By installing Catalyst 9.3 driver ver.: 8.591
                        Openglx showed: OpenGL 2.1 support
                                 --> the same problem with stellarium

My video card is: x1950pro

I hope helps a little.