It shouldn't be this difficult. Haven't ran my S1 for a few months. Also, I upgraded my iPhone to 11 Pro Max. Charged the S1, and attempted to use the Bose Connect app. Unable to make a connection to the app, although the S1 did connect to the iPhone, and tried music play, and worked. Kept going back to the app, and it would time after time direct me to push the BT connect button for two seconds....
Next deleted the app from the iPhone, Pushed in the BT connect button for 10 seconds to clear the list, restarted the iPhone, downloaded the current firmware via Windows 10, after downloading the current updater app. Next removed the battery from the S1. Reinstalled battery. Launched the Bose Connect app, followed directions to open iPhone settings. Connected to the S1. Went back to the App, and same result. Asking me to hold the BT connect button in for two seconds. Tried it again, no luck.
I am having the same problem trying to use my new Pro 16's with the Bose Connect App. The app doesn't recognize the Pro 16's. Is it possible that the Pro 16 isn't compatible with Bose Connect??? I have seen videos of Bose Connect working with the S1's.
As far as I know, the Bose Connect App only works with the S1 Pro systems, not the L1 Pro's. The L1 Pro's only have the L1 Mix App at this point.
I wonder if Bose might rework the Bose Connect App for compatibility with the L1 Pro's, or whether a new app might be developed? Seems reasonable to me!
The L1 Pros use a browser-based utility called the Bose Updater. Not sure what kind of computer you use, but I used my Mac and needed to install the Bose Updater through Chrome.