I messed around with mine last night using the same cd I did the other day when I experienced a surround channel reverb effect.

What I noticed:
1) It WAS in a movie mode.
2) The track that I noticed the "reverb" in was a remix that had some "echo" effect in the stereo mix.

Take a 2 channel recording, add a dash of movie mode, and a pinch (or two) of a simulated 7.1 playback, bake for 5 minutes, and you get some strange echo.

I played the track in 2.1 mode and it sounded great.

Farewell - June 4, 2020