Document FileType doesn't show pdf; works with no FileType selected, or Applications selected

v4.16.3 but this wasn't addressed in the 4.16.4 updates in NEWS.

Reproduce:

1. Set search folder (may be optional)
2. type search term for a known pdf
3. select filetype = Documents
4. No results
5. Change filetype to none
6. pdf result appears
7. Change filetype to Applications
8. pdf result appears

Cheers!