Same issue here.
SIP disabled when checking status with csrutil status.
Tried applying "sudo nvram boot-args="-no_compat_check"" from the machine booted into my admin user to no avail.
Still restarts to the login screen and nothing updated after checking About This Mac.
We need to know what's happening when this happens (goes through the machinations, but then simply reboots with 10.15.1 installed) and how we might fix this. I get an error when clicking on install new OS when using the USB stick option. Stalemate for me.