S6 switches to silent when plugged in or unplugged

[AC Question]

This started a day or two ago. I keep my phone on vibrate all day but lately when I plug it in or unplug it it automatically resets to silent. A notification pops up asking if I want to hear calls or stay silent. How do I stop this so it doesn't change my ringer setting? I need my device for work and don't always realize it has changed to silent.