From the forums it seems that this (amazing) feature only works in some apps with compatible API. I thought Bookends was in that category, but when I try to select text or a previous highlight on a pdf in Bookends, Copy Selection and Link is greyed out. It works in Highlights app.
I asked Jon at Bookends if a native option would be possible (since I really like how their Export Annotations now has a “block” of highlight followed by deeplink at the end of the phrase/paragraph which plays very well with block-based Notes/PKM apps), but they also suggested I check here to see if there might be a Hookmark fix.
I am using the latest versions of apps and MacOS.
Related, I wonder if the current output of selection followed but the deeplink on a new line is optimal. I, at least, usually want the selection and link together in a block/paragraph so that they travel together in block-based editing. Even if not, I usually would put the link in parens at the end of the quote rather than on a new line. I’m sure folks will have various preferences there …