How do I toggle "Do Not Disturb" via ADB?

I would like to enable Do Not Disturb on a phone via ADB. I have located the settings namespace and key which controls Do Not Disturb: adb shell settings put global zen_mode 2 But when I run this command and then get the key its value remains set to "0". If I enable Do Not Disturb manually on the phone, then look at the key, it shows "2" as I expect. I am using stock Samsung S7/S7 Edge phones, with Android 7.0, not rooted. Is there a step missing in order to toggle this particular setting via ADB? Thus far I haven't had issues changing any other settings in this way, so it's confusing why this does not work.