Sound changes blinking screen

Vizio TV and xi6-A box. Tv blinks on and off constantly. TV moves between stereo and Dolby. This doesn’t happen with any other input. SmartCast is fine. Airplay is fine. PlutoFreeTV all works with sound and no screen blinking. Restarted router = no change. Would love any suggestions.

This conversation is no longer open for comments or replies and is no longer visible to community members.