Cloud accounts · Cloud apps on your Mac
Why did my Dropbox or OneDrive folder move after the app updated?
Short answer: The provider moved to Apple's system for cloud apps, which keeps the folder in a CloudStorage folder in your user Library. Nothing was lost, and Storage Studio finds the new location by itself.
Because the provider switched to Apple's built-in system for cloud apps, which places the synced folder in a CloudStorage folder inside your user Library and lists it in Finder's sidebar under Locations. Your files weren't lost — they're in the new place and still in your cloud account.
If you kept shortcuts or apps pointed at the old folder, point them at the new one; Finder's sidebar entry is the quickest way to find it.
Storage Studio picks up the new location by itself the next time you open a window or menu that lists cloud folders, so there's nothing to change in the app. If a transfer or rule used the old folder as its source or destination, edit it to use the new one. See where cloud apps keep files.