Thanks. I had looked at a couple of the reports, and had seen that it was a sign issue on the NaN: specifically, my expected value is the wrong sign (at least on the instances I dug into), which means it's somewhere in the way I produce my expected value (I probably should've just hardcoded the expected, once I knew what my test matrix looked like).

The last I'd looked, the Windows 5.16.0 failure hadn't shown up in the matrix. That should make it easier to replicate, since it is just a strawberry that I should be able to download tomorrow.

Again, thanks.