Can not connect, and it says "Robot was already bound"

Hi, it is a bit of a nightmare, but I can not connect my mower robot 250. I do have a WLAN with 2.4 and 5ghz combined, my iphone shows theres enough wlan at the station.
Now I tried to reboot all, deleted also the app, started again, and although I do so, it always shows "Robot was already bound". But there is no device I could delete. So I am completely stuck...

TranslateView Original Text

With no device I mean there's no mower I could delete on the app.
It just always says network connection failed.

Well, I was really afraid of installing because usually these things won't connect. and...it does not.

Hello, we are sorry you encountered this issue. Please send us error screenshots, device SN code, bound email address, purchase receipt and invoice via private message. Private communication can better protect your privacy. We will verify the device information and follow up promptly once we receive the documents.

Hello, we have contacted you via private message, please kindly check your inbox.