Did you upgrade your speakers to S2 per chance after you installed the S2 app?

If not then simply run the S1 app and “connect to existing system”.

I don’t understand what “it only shows S2” means.

If you did upgrade your speakers to S2 then you must now use the S2 app to control them.

Thanks! I believe my son upgraded one of the speakers to S2. But I have six other speakers which are all only S1 compatible. My computer is showing S1 app but when I click on it, the app automatically goes to S2. I want to delete this app and re-install. Thanks 

Still not quite understanding “when I click on it, the app automatically goes to S2“ - please supply a screenshot  of what is happening here.

Looks like you are on the PC, the S1 app for PC has a dark grey icon. (The S2 icon is a beige color, avoid that).