EEVEE subsurface scattering (SSS) causes artifacts/banding Why am I getting this banding artifact and not getting translucency (e.g through the ear)?  In the various online demonstrations of EEVEE's SSS I've looked at, there's not banding and translucency works.  Is there some setting I'm missing?

My setup is one lamp that's behind Sussanne, and Sussanne's material is Principled BSDF with SSS=1 and transmission=0.  It's Blender 2.8 for Mac OS.

The two images below show the banding effect.  


In render settings, the SSS samples count changes but doesn't remove the banding.  
In render settings, the jitter amount has no effect.  
In render settings, "screen space refraction" on/off has no effect.
In material settings, "subsurface translucency" on/off has no effect.
I discovered through more experimentation that subsurface value set to 1.0 is extremely high.  Values below 0.3 don't exhibit these artifacts.  Also:


moving the light further away from the object reduces artifacts even at sss=1
it's not necessary to turn on screen space reflection/refraction 
SSS translucency does work.  I don't know why it wasn't working when I created those screenshots.  Maybe I just needed to reboot, or maybe I had some weird settings.