I really like the Offline Missions. But after you run an Offline Mission, the Offline Practice is set to the arena used in the Offline Mission you ran last. The Offline Practice arena should revert to whatever arena the player set last, not the arena use in the Offline Mission. I can see this as confusing to a new player. New Player goes into and Offline Mission. Then when New Player goes into the Offline Practice arena, it is not the arena he last used. In fact, it may be a very small arena. New Player may not know how to change the arena.
So I wish that when New Player finishes an Offline Mission, the Offline Arena switches back to whatever arena it was last set to.