[Update] 11/21: The mandatory update has been implemented at 11/21, 18:00 (PST), which is earlier than the original date. We sincerely apologize for any confusion and inconveniences this may have caused.

[Update] 11/20, 19:10 (PST):

Ver.20.9.1 has been released for iOS, fixing the issue where the BGM volume settings in [Options] are reverted to default settings when entering a dungeon. In the event that you do not update the app right away, there will be a mandatory update after 11/21, 18:00 (PST). We apologize for any inconvenience this may have caused.

We have confirmed the following issue occurring in Ver. 20.9. 

Issue details

When entering a dungeon, the BGM volume settings in [Options] are reverted to default settings. 

We are currently investigating the cause of this issue, so please check back at a later date for any updates.

We sincerely apologize for any confusion and inconvenience this may have caused and thank you for enjoying Puzzle & Dragons.