Why is my volume button not working lg g4

[AC Question]

I've got the LG G4 and I've had it almost a year now and I'm not super tech savy so maybe someone can help me. Earlier today the volume up button was perfectly fine but at some point it just stopped working and I can't get it to respond at all. The only thing I can this of is that it slid off a small shelf on to the counter at one point but the drop was only a few inches. Is there a way to fix this?