Running macOS 15.4.1, Simulator 16.0 (1042.1), various iOS devices (iPhone 16, iPad 13" M4)
I log into iCloud and enable iCloud Drive. Running the Files app, I noticed that I can click on "flat" documents (PDF, JPEG, etc) and they work. However, when I click on "package" documents (e.g. represented by a directory behind the scenes), I get a normal download progress, but then an alert "The operation could not be completed. No such file or directory".
This seems to happen with all package documents, e.g. Keynote documents or Reality Composer objcap documents. It does not happen on actual devices logged into the same account.
I've tried completely deleting and rebuilding the simulator instances in question, with no success.