I am wondering if your download of 8.99+GB data is
somehow waiting for a "wifi" connection.
Not sure what you mean by "your"? This is Qt user forum, not Qt developers.
Also, you do not have to download 8.99GB to install one Qt version and QtCreator on Linux!
What exactly did you select in the installer?
Please do not check the whole Qt version, check only what you need under the Qt version (expand the tree).