Hello mcflyathome,
You should be able to make adjustments to your portraits using the steps below:
Use the Depth Control slider to adjust the level of background blur in your portraits.
1. Open Camera
, select Portrait mode, then frame your subject.
2. Tap
in the top-right corner of the screen.
The Depth Control slider appears below the frame.
4. Drag the slider to the right or left to adjust the effect.
5. Tap the Shutter button to take the shot.
After you capture a portrait, you can use the Depth Control slider in the Photos app
to further adjust the background blur effect. See Edit Portrait mode photos.
You can also find those steps in this resource: Take portraits with your iPhone camera - Apple Support
If you aren't seeing that option, does that still persist after restarting your iPhone? Restart your iPhone - Apple Support
Let us know, and we'll keep moving forward from there.