On a Windows 10 HTPC connected via HDMI to an AVR and then HDMI to a TV, graphics card is a Nvidia 1050. There is a second display connected to the onboard Intel graphics card via VGA which runs Frontview.
When I open ET and playback a file, refresh rate switches as it should. Once that video file stops if I re-start it or play a different video file, refresh rate switching does not occur.
If I close ET and re-open it, the same pattern occurs.
Reproducible 100% of the time.