Un install them. you should be able to do that eitehr in the Creative Cloud Desktop app or through the Windows Control Panel.
There is a setting, option, that moist likely turned off (As it is set to be On by default). And that setting, option, is to Uninstall the older version when installing a Newer version (not just a Point release of the same version but a Upgrade to a completely newer version. Like going from 2019 to 2020).
That option, IIRC, is only accessible if you do upgrades individually, IE One at a time. And not available if you click on the Update, or Upgrade, All button.