Reset the Connect by following the steps at the bottom of this article:

https://support.sonos.com/fr-be/article/reset-your-sonos-product
 

Then try to set up the Connect again in the Sonos app by following the instructions in this article:

https://support.sonos.com/nl-be/article/set-up-your-sonos-connect

It could have been deliberately bricked as a part of the very short-lived Recycle program. If the S1 Sonos app still can’t find it, hard-wire it with Ethernet and run my app “Phonos Plus” on iOS, it will tell you if the device can be found and whether it has been DEACTIVATED which is how bricked devices report themselves.