This is my replacement phone from a previous issue but I cant use my camera now and its 3 months old the last one was 2 months old. My girlfriend's iPhone X never has issues and its a year and a half old. I've been upgrading up since the galaxy s6 to the s7, s8, and now the note 9 and every phone has been great until this note 9. I'm afraid to upgrade to the note 10 when it comes out honestly It's a hassle that I didn't pay to send my phone in every couple of months.
Give this a shot. It should help:
Go to Settings > Apps > Show system Apps (click on the 3 vertical dots upper right of screen) >
Camera > Storage > Clear Data and Clear Cache.