Weird issue that started in Sierra - does this happen to you?

[aliensporebomb]

Running: iMac Retina 5k, 27-inch, Late 2014
Memory 32 GB
Graphics AMD Radeon R9 M290X 2048 MB

Configuration: Two external displays, both via thunderbolt2 ports.

Issue: Running youtube, or any other live streaming video platform and selecting full size blanks the other two attached displays.

Same thing happens when I try to run a game - primary display functions, other two go black. If I swipe left I get another "space" but that's not completely ideal either.

This seems to have started with Sierra.

Solution?

 

[FreakinEurekan]

Running: iMac Retina 5k, 27-inch, Late 2014
Memory 32 GB
Graphics AMD Radeon R9 M290X 2048 MB

Configuration: Two external displays, both via thunderbolt2 ports.

Issue: Running youtube, or any other live streaming video platform and selecting full size blanks the other two attached displays.

Same thing happens when I try to run a game - primary display functions, other two go black. If I swipe left I get another "space" but that's not completely ideal either.

This seems to have started with Sierra.

Solution?

Sounds like you have System Preferences > Mission Control > Displays have Separate Spaces un-checked

 

[aliensporebomb]

Curious. I'll give it a shot.