What do you mean by “still inactive device”? Do you mean it appears as offline on the Dashboard? That would be expected if it has internet connection problems. Can you try again with a direct Ethernet connection?
I have had this issue as well, 2 times. One time it was the WiFi (2,4Ghz and 5Ghz on the same SSID, the router didn’t allow connection somehow, fixed by resetting the router.)
The other time it was unclear where the issue was, and re-downloading the image with credentials set (exactly as the try before) and flashing that solved it.