Earlier quoted context omitted.
There is a lot of misconceptions here. There are two parallel tracks of JQuery maintained, with _identical functionality_, one which supports IE8 and less, one which doesn't. JQuery team is supporting both. If they don't behave identically, that's a bug. If you don't need IE8 or less support, you can use the smaller higher-performance JQuery that doesn't support IE8. If you do need IE8 or before you use the other var…
Thanks for the detailed response, that is clearly my mistake. I did an install from NuGet and went with 2.1.1 making an assumption that the latest build was the greatest build and not really doing a lot of research. On my end, it was a browser compatibility mode setting and a meta tag resolved the issue for just my site and is fine for the usecase.
Hopefully the change to calling the variants "JQuery Compatibility" and "JQuery" will help -- although since they are still saying they recommend "JQuery Compatibility" for most sites, I think they should have called it "JQuery" (the compatible one) and "JQuery Future" or "Jquery Non-Compatible" or whatever.
Anyway, you also could have simply dropped in the equivalent JQuery 1.x version for old-browser-compat with no changes to your code.