Custom paragraph style: Styles sidebar versus Find & Replace the list of paragraph styles

Interesting case encountering right now in one documents under my current editorials. A custom paragraph style is present/visible on hierarchy tree in Styles sidebar while not available on the list of paragraph styles in the Find & Replace dialog.
Document history is however not straightforward I need to add it honestly: and .odt exported from master with linked subdocuments, master and the subs used template, furthermore up to 3 short documents were inserted into master without well-managed style usage, etc.

  1. My point is that I am not able in this situation to search for usage of that style in document; a document that has bit more sides than one hundred.

  2. What about the reliability of functionality Search for paragraph style in Find & Replace dialog? I want to remove paragraph styles unused in document however of visibility in certain form. I use for it Find & Replace, search for paragraph style.

No related tickets found in bugs database of documentfoundation, nor in AskLO forum recent couple of years.

EDIT
One more test. Deleting a paragraph style that according to Find & Replace, Search for paragraph style is not used in document. Test results: Deletion not possible due the style usage in document. Unclear however which paragraph in whole document does it - Find & Replace, Search for paragraphs styles does not help as it reports 0 usages of this style.

I don’t rely on Find & Replace to probe for used/unused styles (not only paragraph but also character).

I modify the suspect style by adding a coloured background and/or font colour. If there is no conflicting direct formatting, usage becomes immediately obvious. You can also switch to Multiple View with low zoom factor so that you have many pages on screen.

But it is possible that you have “shadow (or hidden) usages”: no change is visible on screen and you can’t delete the style. This may happen if your document suffers from contorted structure, like supposed-to-be-deleted tables in header or footer containing occurrences of the style, frames with bad positioning, …

It is difficult to tell without an example because nearly every case is unique.