Video Doorbell doesn't start set up / no spinning

Hello, I have a Ring Video doorbell 2. Until yesterday, I hadn't used it for over a year as we were living abroad. Coming back home yesterday, I have reconnected the doorbell as I changed our WiFi password, and it worked fine. However, since this morning the doorbell appears to be offline. Nothing really changed to the WiFi, the only thing I did was resetting the router. I have gone through the set-up process many times, but nothing seems to work. Whatever I try, the video doorbell is not going into set up mode; after releasing the black button the light does not start to spin. I have restarted both modem and router, also not working. Even a hard reset doesn't work! After holding for 15 seconds (or longer), the light is not flashing; I don't think it is resetting. The doorbell is 100% charges as it is hardwired. Any help would be appreciated since this is not working at all.