The Planar Fissure event may disappear from your Travel Log for two intended reasons:
1. Reward Limit Reached: Special reward events have a maximum number of bonus claims. The event will stop giving double rewards once you reach this limit.
2. Event Period Ended: The event is removed from the interface once its scheduled duration is over.
You can view the specific duration and remaining reward attempts for an event in the Event Notes via the Travel Log.
To review your reward history for confirmation: Navigate to Menu >Bug Report > Self-Service > Select Account History > Relic History (4-star or above).