Apple today updated its macOS 12.3 beta release notes to warn macOS Catalina users about a potential boot loop issue when installing the macOS 12.3 or macOS 11.6.4 betas on a separate APFS volume with FileVault enabled.

"If your Mac currently has macOS Catalina installed, installing macOS Monterey 12.3 beta or macOS Big Sur 11.6.4 beta on a volume with FileVault enabled might cause a boot loop when attempting to log back into the previous volume," says Apple.

On a Mac running macOS High Sierra or later, it is possible to install macOS on a separate APFS volume and then switch between versions of macOS, including betas, as if each were on a separate disk. Apple has a support document with more details.