Adding an actual tab character doesn't work with the "Detect Indent" plugin

[Allen-B1]

When I go to Preferences > Tabs and turn "Insert spaces instead of tabs:" off, nothing happens.

I only managed to turn it off after I unchecked the "Detect Indent" plugin

[jeremypw]

This seems to more due to whether the open document contains pre-existing tabs or not. If you start with an empty document or one with no indents then the headbar settings are honored as expected (in version 8.0). However another look into these two plugins and how they interact with themselves and the editorconfig plugin should be undertaken.