You can follow this post for information about Known Issues in the 24.0 Patch.
[Resolved 7/26] The team is aware that Achievements that granted Sunken City cards were able to be claimed after Patch 24.0 went live and that for many players those cards were already claimed. This is not a bug, but part of the shift from one expansion period to the next. Those are cards that were given on the Sunken City Rewards Track, converted to Achievements in anticipation of the end of the Sunken City expansion period. Some people have already received those cards and completed those achievements; others will still have a chance to earn those free cards by completing those achievements later.
[Added 7/26] The team is aware that the background is missing from the Rewards Track in Patch 24.0.
We will continue to update this post as we get more information.
Kurt Ocher
Hello everyone,
You can follow this post for information about Known Issues in the 24.0 Patch.
[Resolved 7/26] The team is aware that Achievements that granted Sunken City cards were able to be claimed after Patch 24.0 went live and that for many players those cards were already claimed. This is not a bug, but part of the shift from one expansion period to the next. Those are cards that were given on the Sunken City Rewards Track, converted to Achievements in anticipation of the end of the Sunken City expansion period. Some people have already received those cards and completed those achievements; others will still have a chance to earn those free cards by completing those achievements later.
[Added 7/26] The team is aware that the background is missing from the Rewards Track in Patch 24.0.
We will continue to update this post as we get more information.
Kurt Ocher