Watching movie via HDMI connected to MACbook

Apple did it again! They moved all movies from iTunes to another app called "TV." Okay, I can still watch movies on the MacBook but when connecting it to an external TV using an HDMI cord, all I see is the desktop background. I open "TV" on my MacBook to view movies and it does not show on the external TV. I tried turning off the external TV, unplugging the HDMI cord and then reconnecting and turning external TV back on and still nothing. Apple makes it so difficult sometimes! A windows computer would automatically connect.