I cannot get the rainbow costume. I'm now at this moment of posting on level 395. There is no way I haven't won 5 levels in a row* with all the characters (Tiffi, Yeti, Nutcracker, Odus, Misty, and even the elusive Red Rabbit) since the opportunity emerged after gold was accomplished. My app (PC/Laptop) keeps resetting the levels won back to 0 once I close it for the day or for a few hours. I have screenshots of this happening. This wasn't an issue with the silver and gold costumes, so I'm at a lost as to why this is occurring. I know the costumes don't add any special abilities, but that's not the point. Appreciate any feedback even if I'm doing something wrong.
* - Not seen any character appear/be an option for 5 consecutive levels.