Thank you all for this feedback. It's a lot to read but I'm carefully reading each report on this thread.
The main problem here is that this is not happening to me and that makes it almost impossible to fix. If I can experience it for myself, and replicate it, then I can start testing and trying different things until I can fix it for myself.
Switching to NGA wouldn't have changed things, BUT we did add a new server a few weeks ago and that is a huge change. It feels to me like something with the new server is causing this issue. It's not the extra load on the server placed by our extra traffic, I'm sure of that.
I've been out of town for since Thursday morning, but I'm back in my office now and will continue to investigate this. I really appreciate everyone's patience as I figure this out!