- Open preferences page "Folder Tabs / Folder Tab Bar".
- Change tab bar position using its context menu from vertical to horizontal or the other way around.
- Bug: The enabled-state of the checkbox "Use popup menu when tabs exceed available space" including those of its subordinate ones isn't adjusted (in both directions). When using the preference page's "Tab bar position" combobox instead, it is.
A fix will be in 13.14.1.