On Xbox Series X
What you were expecting to happen, and what actually happened:
Expected: Arena Deals only offer troops that are not already ascended to Mythic. Actual: Received offers for Goblin (Common) and Goblette (Rare.) Both troops have long been Mythic - I have 180 copies of Goblette and 2,049 copies of Goblin.
How often does this happen? When did it begin happening?
This is the first time I’ve seen this behavior, and these were the first two deals offered for Arena today.