Sometimes when using the Apple TV simulator, the simulated Siri Remote goes missing. Toggling it's visibility does nothing - it's extremely frustrating!
This happens when you are using external monitors. To bring it back, use the command line to reset the position of the remote:
defaults delete com.apple.iphonesimulator "NSWindow Frame Apple TV Remote Window"
Then, re-launch Simulator.app
, open a TV and SHIFT⌘R again!