[6.7.0] Slower network speeds

I've seen several people reporting slower network speeds (tests and real work performance) are slower after upgrading to 6.7.0

I've seen this with the Speedtest plugin and a Win 10 VM going to speedtest.net.  Speed is about 200Mbps slower than in version 6.5.4 (in my case).  Others have seen the same issue of speed difference between 6.6.7 (normal expected speeds) and 6.7.0 (slower speeds by 200-300Mbps).