What I read above doesn't read right.
What you want to do is:
1. Download the BS update.
2. When it's done DLing, the installer will open and ask you to approve the rest of the install.
3. DON'T APPROVE the INSTALL!, close the app and eject the package. The BS installer will sit in your Applications folder. Just leave it there all nice and comfy. Just make sure you don't accidentally execute the whole thing. I'm being hounded to install Monterey Beta.
4. See what happens with what you are trying to do after you do this.
5. If it fails, restart your machine.
Also look under the OS install banner for some smaller type indicating that there is other software to install that you might need. But it's not the BS installer that now should say "Open". Click on the small text link, not the "more info" inside the box with the OS. That should bring up a list of what is going to be installed.
Anyone feel free to add to or correct me.
Good Luck!