Is it possible that it's to soon to install the update, because I don't even see it when I go to software updates on my Mac.

@SMR1 What version of macOS Ventura is running on your test Mac? Some of the earliest versions of Ventura may not support Safari 17.3 (I didn't check to see what the minimum supported version was since all of our Ventura machines are on 13.6.0 or higher)

Our test Mac's are 13.6 and higher.

This is where I download all my safari updates.

macOS Safari Full Installer Database. Download Directly from Apple! (mrmacintosh.com)

The install fails when I run it locally.

I use this script to just download the update through Apple's built in updating tool.  Works fine, but doesn't really give you a version control option.  It just downloads the newest version Apple has available for that machine at the time it runs.

I just tried that, must be one of our security tools that's blocking the install and the script from running. It's weird, because I've been using the standalone for the last 3 updates and haven't had any issues.

Looks like the script did attempt, but didn't work, because in the log the command doesn't see Safari 17.3 as an available update.