https://9to5mac.com/2023/02/14/dropbox-macos-external-drives/
Mac users who also use Dropbox have been experiencing some issues recently. That’s because Apple killed an old extension used by cloud services with macOS Monterey 12.3 and replaced it with a new API. Dropbox is finally working on a new version of its macOS app that works with this API, but it comes with a downside. Users will no longer be able to store their Dropbox folder on external disks.
macOS Monterey 12.3 was released in March 2022. But even before the update, Dropbox had been warning its users that the macOS app would lose some of its functionality due to the latest changes made to Apple’s operating system. For example, it’s no longer possible to open online-only files (placeholders) stored in the cloud…
Dropbox currently lets users store their Dropbox folder on an external storage. However, this will no longer be possible even after the update with support for macOS Monterey and macOS Ventura. This is because all content from cloud apps on macOS will now be moved to the ~/Library/CloudStorage folder for privacy reasons…