On macOS, we are currently unable to retrieve your collection for two reasons:
1) On 2021-08-25 WotC removed collection info from the game logs with the patch 2021.8.0, making us unable to read your collection.
2) We applied a workaround on Windows that is not available to us on macOS (same issue as the Draft Helper).
We will be able to restore collection features on macOS if either WotC adds the log statements back, or until we manage to implement the workaround above on MacOS as well.
We are sorry for the inconvenience and are working hard to fix this!