Here are some command line options that I have used recently that should help: - MacAppStore Link for Catalina (and others ... https://osxdaily.com/where-download-macos-installers/) https://apps.apple.com/us/app/macos-catalina/id1466841314?mt=12 - using softwareupdate terminal command to download installer
https://scriptingosx.com/2019/10/download-a-full-install-macos-app-with-softwareupdate-in-catalina/ - installinstallmacos.py https://github.com/munki/macadmin-scripts
