I frequently set my Galaxy S7 to vibrate mode, however it keeps turning vibrate mode back off. I can't figure out what exactly is causing this.
I know at least one condition that triggers this consistently. Whenever a call is ended or rejected for any reason, vibrate mode will turn off on its own. To get around this, when I go to bed I put the phone in airplane mode to prevent any calls from coming in at all, but leave WiFi on so other things still have connectivity. Unfortunately, I discovered that vibrate is still turning off even when in airplane mode.
This is becoming a major problem as I need to trust that my phone will remain quiet when I need it to.