Try a wipe cache partition. My media was constantly pausing and this worked for me.
Step 1: shut off your device.
Step 2: press and hold the volume up button and the Bixby button, then press and hold the power button.
Step 3: when the logo appears release all buttons. (the "installing system update" screen will pop up but just wait a few seconds)
Step 4: on the Android Recovery menu, press the volume down button until you get to "wipe cache partition" and press the power button to select.
Step 5: when that is completed, the "reboot system now" option should be highlighted, select that with the power button and the device will restart.