The strange thing to me is that Nvidia shouldn't be involved here. A USB-C port is likely to be wired to the Intel chips only. As a DisplayPort the USB-C is wired to the Intel GPU. And gnome-shell by default will use the integrated Intel GPU only for the desktop.
Please reproduce the freeze again, then reboot and run:
The strange thing to me is that Nvidia shouldn't be involved here. A USB-C port is likely to be wired to the Intel chips only. As a DisplayPort the USB-C is wired to the Intel GPU. And gnome-shell by default will use the integrated Intel GPU only for the desktop.
Please reproduce the freeze again, then reboot and run:
journalctl -b-1 > prevboot.txt
and attach the resulting text file here.