Can open tome for event, before it's unlocked

iavatus

1) Click on Bone Chill (the event information)

2) Click on Collection

3) Click on Snow Skulls or Snowman-in-the-box

4) Click on event tome

Can open and view level 2 of the tome, before it's unlocked. Unable to select challenges to start them, only view. Restarting the game didn't fix/stop this. No other anomalies noted.