Hello!
This loop usually happens when the device cannot properly verify your account online. Make sure the PC is connected to a stable internet connection, then on the sign in screen choose Sign in options and select Password, not PIN. Also check the keyboard layout at the bottom right to ensure it matches your usual typing.
Restart the PC once, then try again with your full Microsoft account email and the latest password you confirmed online.
If it still fails after multiple verified password changes, I suggest restarting setup or using the Reset this PC option to start fresh, since the initial account setup may be stuck.