Hello Mimk_apple,
Thanks for using the Apple Support Communities! We'd be happy to assist with this.
Could you please confirm if you're having this same issue with other embedded images as well or just QR codes?
Is your iPhone fully up to date? These steps can help you check:
1. Back up your device using iCloud or your computer.
2. Plug your device into power and connect to the internet with Wi-Fi.
3. Go to Settings > General, then tap Software Update.
4. Choose the software update that you want to install. You can choose to stay on iOS or iPadOS 15 and still get important security updates. Or you can choose the option to upgrade to iOS or iPadOS 16.
5. Tap Install Now. If you see Download and Install instead, tap it to download the update, enter your passcode, then tap Install Now. If you don't know your passcode, learn what to do.
If you're fully up to date, you may also want to check if "Protect Mail Activity" is currently enabled in Settings > Mail > Privacy Protections. If so, try disabling that temporarily to see if that improves things.
Cheers!