Same problem here. I was trying to transfer some things from my old iPhone (old... iPhone 11 Pro), and something didn't went well. No problem. But now the new iPhone is stuck, and I've to surf internet to try to understand how to unblock it... :-(
(after 15' of trying)
At the end I had to do long-press the main button, select "Start Again", and restart the configuration of the new iPhone... I hope it will work.
(other 45' of reset to factory and trying again - while charging, as I've now only 50% of battery...)
I reconfigured, but it was quite different from the previous configuration... like 2 different iOS-start-and-configure-OS versions...
(other 15')
Now it's updating to iOS 17.5.1 ... :-(