Workaround to Autocomplete drop-down lists when the value list is set to "Also display values from second field"+ "Show values only from second field"

I am new to this forum. I joined because I am pretty new to Filemaker and I have just come through a problem I do not know how to solve.

The Filemaker has, among others, 2 DB tables: Books and Artists. They are both related through a N:M (many to many) relationship.

The user can select an Artist on the Filemaker solution, and then relate a few books to that artist.

The user CAN NOT relate any artist to a previously selected book: this option oes not and will not exist.

I would like to create a drop-down box for Book Title, but store the Book ID. I would like the user to be able to type the first few letters of the book title and have it cycle through the list so they don't have to scroll through 5000 titles.

I have tried Manage Lists with the first field (BookID) stored and only show the second field (Bookitle), but then the auto-complete doesn't work (it doesn't work when the list is set to "Also display values from second field" or "Show values only from second field" or "sort by second filed"). This is so basic, I must be missing something. Could you please help me?

Thank you so much!