I noticed I can no longer back up to iTunes, I presume this is because the iOS 16 beta is installed but I wasn’t finding any posts to confirm this, I was wondering if this seems to be the experience across the board?
iTunes backup while using ios16 beta
Hello Greenday8616. Device backups happen in Finder. This was first introduced with macOS Catalina 10.15.
How to back up your iPhone, iPad, and iPod touch with your Mac
If you have more questions about backing up your device, I recommend asking over in Apple Support Communities run by Apple Support.
—Jason.
Can confirm, i have the iOS 16 Public Beta 5 and i have the same issue. Using iTunes on a windows PC. My theory is that iTunes has not been updated to support iOS 16 yet. This should be fixed in the official release.