When BiblioAddsAuthorities is on, personal name headings that include question marks do not automatically generate authority records, even though the exact same name without the question mark works properly.
To reproduce this bug, create a new record and put, for example, "Smith, John," in 100$a and "1920-1980?" in 100$d. Save the record. There will not be any authority record linked to that heading. If you do the exact same thing but do not include the question mark, an authority record will be created.
*** This bug has been marked as a duplicate of bug 5410 ***