Notes created on iOS 15, macOS Monterey might not work on older versions

[iMore.com]

Apple's iOS 15 and macOS Monterey are both now available as part of the public beta program, but people who have installed them could be left with notes that can't be opened by other devices. In fact, any note created using Apple's betas could simply disappear, making them completely unavailable on some devices.

Full story from the iMore Blog...