I have a similar problem.
The switch itself flicks (it's not stuck) however it doesn't vibrate or make any sound. The volume buttons don't work either however I can still hear music. My sound doesn't work for things where the silent button is needed to be off (ex. Instagram videos, snapchat videos, etc.). I have tried going on to settings and turning it off silent but it still doesn't work. I've also tried turning it on and off and I haven't dropped it. Please help!