[PROBLEM] new user can't start on rpi4

[philrandal]

It could be your router has already assigned that ip to another device.
https://www.advanced-ip-scanner.com/
Try that to scan your network.

There is another post just like yours here, it might be an idea to check that out and maybe you can both get the help you need..

I use the Fing app on my Android phone to scan my network for newly setup Pis and other devices.

Phil