No, I have not "Insert spaces for tabs" enabled. It seems that formatter considers the tab size equal to 8 spaces. And when I make first indent (I have 4 spaces for indent size), it inserts 4 spaces. Then I make second indent and it replaces first 4 spaces by two tabulations.
In your video you have set code formatter "Tab policy" option to "Mixed". In your first comment you said that you use the option "Tab". What is correct? Do you have problems with both options?
In Preferences->C/C++->Editor->Typing you should see the current identation size and method. Check this.
It's very strange but "Tab policy" is completely ignored for first indent level. I set this option to "Tabs" and still got four spaces instead of the tabulation. Only after auto-formatting all source file with Ctrl+I indenter start work properly.