Same for me. I have completed league 4 twice today. I am not getting promoted to league 3 . It just restarts league 4. Very frustrating. Needs to be fixed.
Great event. Very achievable. However, there seems to be something wrong with the event chest where you pay 18000 coins to open 10 times. I have done this twice and each time I only saw 8 chests to open. Seems to be missing 2 chests. Please fix this and reimburse. Username - Superfonz. Thanks.