I have been able to add a Sonos Port on a recent firmware version using the new v80 App (iOS). However, a second Port that was on a much older firmware version can simply not be added. I have also been unable to add a Sonos One (also on older firmware) - in this case the speaker is partly added to the system but then the mandatory firmware update fails during the setup process. I have tried this on: (1) Different networks. (2) Wired and wireless. (3) On my existing and a new Sonos account.
I tried to downgrade to S1 to attempt updates this way - but the downgrade option has not been developed for v80 App and is not listed on the roadmap (so I assume this will take some time).
Has anybody been able to find other workarounds? Sonos customer support is uncontactable due to all the App issues resulting in customer service being overloaded but it also seems that customer service just blames the Wi-Fi network which cannot be the case for me as I tried this on two networks.