Slow Incoming Connection

I have a great connection, and speedtest.net shows a very good ping (70ms or so) and great upload/download speed.

But recently, over the last 2 weeks, I am no longer able to use Windows Remote Desktop or use similar services like TeamViewer.  When I try, I can connect but it is incredibly slow.  How slow?  If I'm patient enough to see my login screen (about 60-90 seconds after I connect), typing my password takes another 60-90 seconds before it registers that I typed anything.

I don't now what's going on.  My router settings haven't changed (for example, the Remote Desktop port 3389 is still forwarded to my computer's correct IP address).

I've tried for multiple locations (from a few miles away on another Cox connection, or from my office building where we have very high bandwidth, or even from my cell phone's hotspot and other locations like coffee shops).

Any ideas what has made my incoming connections slow to a crawl?