I never installed M3 until last year, which should have been well after these problems.

However I think I fixed it.  I overwrote the M3 geometries in the default runtime with the M3 geometries from the new download.  Not sure why reinstalling it didn't fix it in the first place, but maybe I was somehow not overwriting that old file even when I thought I deleted everything.

Bottom line is check the

runtime:geometries folder (default runtime.)  Look at the DazPeople folder, that's where it seems to be loading the geometry regardless of whether you install M3 in a different runtime.