Camera standalone app works well. It also works with Instagram, WhatsApp, Messages and Facebook.
I've tried restarting the phone, reset privacy settings and restarting. All my camera privacy options are turned on for these apps. I'm surprised to see a lot of mention about this on reddit and not a single thread on Apple.com
iPhone 15 Pro, iOS 18
That means that no one else has reported this in this user-to-user forum. And what is “a lot”? There are 2 billion iPhones. “A lot” might be 2 million (0.1%). Have you seen 2 million posts on Reddit
As it works with some apps, it is most likely an issue with the apps where it doesn’t work. If the camera is set to “on” in the app settings, try turning it off, then back on.
Perhaps a long shot:
Do you have a 3rd party VPN installed, even if you are not using it? If so, delete the VPN profile in Settings/General/VPN & Device Management/VPN, then restart your device. Don't just turn it off; delete the profile. If that fixes it, you can try reinstalling VPN, but probably shouldn't.
Camera is not accessible from other apps like Linkedin, Signal Amazon or COVVE Scan.
