I wonder if others have the same issue on Monterey: Read-write disk images are not opening automatically when double-clicking the .dmg file (that is, the disk image is mounted by its window doesn't open). Sending this command in Terminal does NOT help: defaults write com.apple.frameworks.diskimages auto-open-rw-root -bool true ALL read-write dmgs are affected. There weren't issues on earlier systems. (I did submit a bug to Apple and they asked me for my sample dmgs).