To my understanding, locking the inspector is designed to tie the inspector to a particular editor pane, so as to describe the document shown in that editor even after focus is claimed by, and navigation takes place in, the opposite editor.
But sometimes a locked inspector remains set on a particular document without regard to navigation in its associated editor. By observation, a locked inspector will respond to navigation in its editor only when that editor has focus. Otherwise it may linger on a third document that isn’t among those then being edited.
For example: Inspector unlocked. Outline view in the left editor. The right editor has focus. We navigate to a doc in the binder and lock the inspector. Back arrow in the right editor: inspector focus correctly follows. Click on a document in the left editor’s outline view. Right editor follows, but inspector remains set to the back-arrowed document, not active in either editor.
Similarly, with the inspector locked to the right editor, let’s give the left editor the focus. Now let’s click on the right editor’s back arrow. The right editor positions to the desired doc, but the inspector remains fixed on the prior one. With a second click on the back arrow the inspector does follow; that’s because the right editor took the focus with the first click.
Same applies to Scrivener Links. They’ll navigate in the unfocused editor, but an inspector locked to that editor won’t move along.
I’ve also definitely had a case where the locked inspector navigates with the non-associated editor, but I can’t reproduce it at the moment.
Rgds – Jerome