Adding bookmarks to text on a page with inherit zoom

Hello! 

I've been wrangling with a problem: I'm exporting PDFs from InDesign with bookmarks, then opening them in Acrobat Pro DC and selecting Save As -> Optimized PDF. I have the Images, Fonts, and Transparency box checked. "Discard Bookmarks" in Discard Objects is unchecked, as is "Discard Invalid Bookmarks" in Cleanup, and everything is unchecked in Discard User Data; I find I get the balance between image quality and file size that I'm after.

However, all of my bookmarks unlink. I can reset the bookmarks for pages, and inherit zoom works - the bookmark will jump to the top of the page, whatever the zoom level is. But when I select a heading within the paget, and I'd like the bookmark to place that heading at the top of the frame no matter the zoom level, it doesn't work. Inherit zoom just jumps to the page which the text is on, without focussing on the heading - so if I'm zoomed in quite far, I don't see the heading at all when I select the bookmark, just the top of the page.

I hope that makes some sense! Has anyone come across this problem before?

Thanks!