Not genuine Apple Camera message

So I have my iPhone 12 Pro Max. I’ve had it since 2020. A little after I got it (through Xfinity) I got a “not genuine apple camera) in my settings I’ve read it was a glitch for a while. But ever since portrait mode doesn’t work purely on my back camera. It did once for a day after a update (can’t remember which one) then stopped working. I don’t want to pay to replace my phone since I haven’t gotten it fixed. I got it this way. Is it just broken or should I suck it up since it’s been 2 years and just replace it?

[Re-Titled by Moderator]