@rich o brien said:

I'm sorry Fred.

😆
Not you, Rich... 😛

It's just that sherwood111 starts this thread with sole accusations, but when it finally turns out to be something caused by something else, it would be appropriate if he expressed an apology... 😉

Selecting by fence draws a rubber-banding box for me on a similar set up in v2015.
Solid lines left-right, dotted right-left, with different outcomes of partially included geometry etc as in earlier versions...
😕
Try alternative Preferences > OpenGL settings ?
Are you Graphics Card drivers up to date ?