Camera .5 option in photo

Yes, this looks like the built-in Camera app. I’ve never seen this issue reported before...

If a restart didn't help, you can try a restore. First from a backup, then as a new device, if still didn't help.

Restore: https://support.apple.com/en-us/HT204184

Apple’s general camera troubleshooting suggestions:

https://support.apple.com/en-us/HT203040

If this is the built-in Apple camera app, there's a lot more that's wrong with that screenshot than just the zoom...

Try these two troubleshooting methods. Perform a Restore only if a Restart doesn't solve your issue.

Restart instructions: https://support.apple.com/en-us/HT201559

Restore instructions: https://support.apple.com/en-us/HT204184