4 white dots in the corner of the screenshot

One possible explanation for these white dots could be a software glitch or bug. To address this, I recommend updating your iPhone to the latest version of iOS. Sometimes, software updates include bug fixes that can resolve issues like this. You can check for updates by going to Settings > General > Software Update on your iPhone.

If updating your iPhone doesn't resolve the issue, it's possible that there may be a problem with the hardware, such as the camera sensor. In this case, I suggest reaching out to Official Apple Support or visiting an Apple Store for further assistance. They can help diagnose the issue and provide a solution, whether it requires repairing the device or providing a replacement.

Additionally, you might want to try resetting your iPhone's settings to see if that resolves the issue. This won't delete your data, but it will reset your settings to their default values, which can sometimes fix software-related issues. You can do this by going to Settings > General > Reset > Reset All Settings on your iPhone.

I don't see any dots in the the 4 corners?

Do you mean the re-sizing handles?