In the "Arranging Chapters in the Navigator" section of the LO Help (found by searching for "arranging;headings"), it says "To undock the Navigator, double-click its frame." It should say "To undock the Navigator, double-click its frame while holding the Ctrl key."
The "Navigator;docking and resizing" search leads to "Docking and Resizing Windows" which does have the correct instructions. Maybe the above instructions should be replaced by a link to that instead?
Good catch, thank you!
Patch submitted to Gerrit:
Stanislav Horacek committed a patch related to this issue.
It has been pushed to "master":
tdf#95626 add holding Ctrl key to undocking Navigator