AC 500 The device does not connect to the application

I had this problem with my AC500 + B300S. When I connected it for the first time, it wouldn’t connect to the app, it said that some account was already linked, I wrote to Bluetty, they said that they had unlinked it and asked me to connect it. So I did, connected for the first time, updated, and after that the device disconnected and wouldn’t connect anymore. It finds it in the search, but it says UNKNOWN123456.
Can anyone tell me how to solve this problem and connect my AC500 to the app?

Hi @john280386, Can you tell us the SN number of your AC500?
Meanwhile, can you take a screenshot about the alarm of “UNKNOWN123456”?
It seems that you have contacted our customer service team, can you tell us the ticket number too? We will inquiry our colleague about this matter.

AC5002308001525410.

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Hi @john280386, We have checked and found that your AC500 is not configured with Wi-Fi. Please try resetting it through “My Device” in the app.

If you are unable to access it, please take a screenshot and share it with us so we can investigate further.