Button found & shown but ADD DEVICE in app not working

My first contact with Shelly and first product of many others ordered.

Could find and bind the button, set fixed IP, updated FW.

Now in cloud app under DISCOVERED DEVICES the button is shown an after I hit ADD DEVICE I can enter name, room, etc.

But selecting DONE always gives me something like „device might be sleeping“.

I have put it on a power supply, it blinks blue, even pressing the button before or while trying to finialie it via DONE button always gives me this rejection.

Tried it on Android and IOS app. Same issue.

Thanks for hints!

Thanks, but as mentioned, it is connected to a power supply.