Find 'including styles' is erratic

I am trying to use the find ‘including styles’ option. Sometimes, this option shows erratic behaviour.

  1. I am searching for “footnote text” style. It matches a couple of footnotes that are in this style, but it doesn’t match others that are also in this style (or at least that is what libre office says when the cursor is on the given footnote. Those that are not matched are not in view. At the same time, some passages that are in the required style are not in view.

  2. If I scroll down and repeat the search, passages that previously were not matched are matched. Again, not everything that is not in view is matched though it should be, and not everything that is not in view is not matched.

  3. If I zoom out to see all pages at once and repeat the match, it seems that everything is matched that should be matched.

I this assume that matching has something to do with wether or not a given page is in view. At the same time, this does not seem to be entirely accurate, for the reasons given above.

Does anyone have any idea why that could be the case?

The documents I am working on have been converted from word docx. My libre office version is