Hi @FILIBAO , thanks for reaching out and sorry for the delay in getting to your message.

At the moment, our team is investigating an issue where the Sub settings are not behaving correctly on iOS devices running the current version of the Sonos App. While we wait for this issue to be resolved in a future update, one workaround would be to temporarily use an Android device running the Sonos App, if you happen to have one available to use/borrow.