It appears that the S3 Beta on the latest iOS update doesn’t work. Does anyone know what the current state of this feature is?
I´m not sure if by "latest iOS update" you mean latest iOS or latest Joplin for iOS.
For me syncing to a s3 compatible bucket on Storj works fine on the following setup:
Latest Joplin on my ancient ipad running iOS 12.5.5.
Latest Joplin on macOS Monterey 12.5 (M1)
Latest Joplin on Android 12.
Have been running s3 sync for 2 days now. Solved a problem with Dropbox sync regularly stopped working on the Android device.