So G8M got deformed, too...
So no sooner do I find weird shenanigans in my g3m, than I find discombobulations in my g8m. Anyone recognize this one (you can see which body parts are being bent to reveal the distortions. My quick check revealed no other such problems in other parts)?

Comments
Never mind, I realized I don't need to go all nuclear and reinstall everything, I just have to change names of relevant folders in data/g3/male/morphs, or whatever it is, until I zero in on the problem. I just did that with the top-level morphs folder and fixed it, so I just need to do the process of elimination bit to find the exact problem.
Duh. :D
Could be caused by the "Man Hippo" character - have a look at "Currently used" with the "Show Hidden Properties" option activated. https://www.daz3d.com/forums/discussion/292046/g8m-bending-glitch-help-please