This is what I did in Germany.
Tried everything, no luck
Waited 24 hours
reinstalled the app from app store and selected China mainland
reset the camera by pushing reset for >10 seconds or so until a relay clicks. The camera reboots
resetted camera with a short push, it started talking
Everything worked then. I got a message to install new firmware 5.5.1.197, so I did that. After that, the camera was online somehow, but I could not get an image of it
I then have made the in-app update to a newer version and got a new firmware update to 5.5.1.200 for the camera. Since then, the camera does not connect as usual. :-(