@neetesha I was only able to see the pre-installed bookmarks after installing Android Opera.
I uninstalled the app, and shut down and restarted the phone. I logged out of the desktop app and reinstalled the Android app. This installation deleted all of the sync items from the sync server but was a "clean" install.
After 3 log in attempts, I finally was able to successfully log in and sync the account. It then took about 15 minutes for the bookmarks to appear on my Android phone. The history and opened tabs did not sync.