Hi, William.
Yes, The Events Calendar is the free/core plugin that is required to be installed and active in order for our add-ons to operate.
For your update issue, please delete The Events Calendar and Events Calendar PRO plugins and install a fresh version via the wp-admin plugin installer.
Deleting The Events Calendar or its add-on plugins will NOT delete any of your data if you delete it via the WordPress plugin manager because that’s how we’ve decided to code our plugin.
FYI: deleting any plugin via FTP or cPanel’s File Manager (i.e. deleting just the files from the server) will also ensure a plugin gets deleted (if you delete the entire plugin folder) without removing any data from the database. This can sometimes be helpful to know in cases where a plugin does run an uninstall routine to delete data (again, our plugins do not run such a routine at this time and probably never will).
You can also see the difference when you click to delete a plugin, like this.
Please let me know how this goes for you.