I made a bunch of changes on my iPad using lightroom and separated the photos into a separate catalog. Now I am on my computer looking to export these files and my changes are not there. nor the catalog. But I see the photos were removed from the catalog made on the PC prior to the changes.
With a single Adobe Id you can only sync/work against the same catalog. Using a new catalog with the same id will trigger a clean up of your back-end. But Lr Desktop should bring up a caution alert about this.