iPhone X Volume/Mute malfunction

Hello. I have a problem with my iPhone X that suddenly got issue. The Volume Up/Down Button suddenly not working, the Mute switch is not working either. And then, my iPhone doesn't even want to play any video or audio (from Photos App, Youtube, Twitter, Instagram, anything really). I cannot hard restart the iPhone (Volume Up > Volume Down > Lock Button) since the button is malfunctioning. However, when I connect to a headphone (Wired or Wireless), I can play any video or audio, but the Mute and Volume Up/Down is still not working. When I disconnect the phone from the headphone, I can't play any video or audio anymore. Can someone tell me a fix? I tried to shutdown the phone, no luck. I tried to Reset All Settings, no luck. I tried the Reset Network Settings method (This fixed the video and audio problem for 3 days before the issue came back, but not the buttons). I really hope I don't have to Restore my iPhone to factory settings and lost all my personal data.