Same problem. Followed the installation process from the description. It's exactly the same how I did it on my Pixel 3 the past 3 years.I tried sideloading the OTA (downloaded from: https://developers.google.com/android/ota), and that failed as well!! I got an error like this:
"Error applying update: 7 (ErrorCode::kInstallDeviceOpenError) E:Error in /sideload/package.zip (status 1)"
I don't know what's wrong! Please help!
Have you found a solution? I absolutely cannot install the update. Tried Nov, Dec and Jan OTA via ADB and system OTA update.