Headphones are plugged in but sound still comes out of device speakers

I just received a brand new Samsung Galaxy Tab A SM-T380. Fresh out of the factory box, I plugged in headphones, but the sound continues to play through the devices speakers. I tried three different pairs of headphones, snapped and clicked in place, but still no sound comes out of the headphones, even twisting and manipulating the jack doesn’t even cause a crackling or stuttering, just dead silence. Does this mean the headphone jack is broken or is there some kind of setting or fix for this?