Blizzard have commented on issues players have been having with unlocking appearances for the Cloak of Infinite potential, and it seems we’ll have to wait a bit for a fix. The issues will be resolved in the patch after the War Within launches, and any missing appearances will be retroactively given.
We are aware of the issue some players are encountering preventing them from unlocking all of the appearances associated with the Cloak of Infinite Potential after having earned Infinite Potential XII.
In the next patch after the launch of The War Within, players with this achievement will receive any missing appearances.
Thank you!