Siri - "Hey Siri" has stopped working

[Drifty_Child]

MBP 2018 / 15" / Latest Mojave version

As of today, "Hey Siri" refuses to respond. (Pressing the Siri key manually and then speaking a command *DOES* work, and my microphone works in other apps). I've tried restarting my computer, and nothing has changed. I've double-checked my system preferences, and "Hey Siri" is still toggled on. Any idea what this could be?

 

[Rodan52]

I know it sounds trivial but try turning Hey Siri off in preferences, restart your device, turn it back on and restart again. It’s possible the plist for Siri has been damaged.

 

[Drifty_Child]

I know it sounds trivial but try turning Hey Siri off in preferences, restart your device, turn it back on and restart again. It’s possible the plist for Siri has been damaged.

I've now tried that, but it didn't work. I even left Hey Siri (and Siri itself) off for a week, but now that I've turned it back on, it's still not working.