Preview: PDF Highlighting & Search Stop Working until Restart

A problem has recently become much more prevalent for me when using Preview to search PDFs for text (using Command + F or the search box in the upper right). At first, everything generally seems to go fine:

1. (as it should be) a list of thumbnails appears in the sidebar, indicating all of the pages that contain the search term.
2. Generally, though not always, the term I search for will be highlighted on the first page that it occurs on.

But, after this, things quickly start malfunctioning:

1. Generally speaking, if I click on thumbnails lower on the list, Preview will take me to that page in the PDF (like it used to). But, it will no longer highlight the searched for terms.
2. Instead, Preview will make a low-pitched beeping noise of the sort that occurs when one tries to perform some un-permitted action in a variety of mac situations.
3. Furthermore, once this occurs, I cease being able to make any highlights at all in the document I am viewing with Preview. In fact, I can't even select any text any more.

Below is a list of unsuccessful efforts to resolve this:

1. Closing the side bar does not work to resolve this.
2. x-ing out the search box in the upper right does not resolve this.
3. Selecting the "Tools" menu and then "Text Selection" does not work either, nor does clicking on the text selection icon in the edit panel.
4. If I quit preview and then re-open the PDF, I am able to highlight again. But, the problem will re-surface as soon as I try performing another search.
5. Working with the same files in other PDF programs (e.g. Skim, Acrobat, etc.) poses no problems. I'm quite certain it isn't a problem with the underlying PDFs.
6. None of the responses to this question resolve this. (indeed, I supplied one such response myself a while ago, but that trick and the others no longer work).

I've used Preview for many years without problem. This issue started cropping up relatively recently for me, I believe within the past 3-4 months. I had hoped that upgrading to Catalina might resolve it, but it did not.

I'd like to think I am fairly sophisticated with computers (I have a reputation of close to 8,000 on the main stackoverflow page), but I am baffled by this. I also don't have a good handle on how I can get diagnostic information or how I can create a reproducible example.

Any leads on how to tackle this would be greatly appreciated.