REVTex 4.2 bibliography missing space after first author name

I’ve got a document in REVTex (based off the apssample.tex template) that is exhibiting some odd behavior in the bibliography: For papers with two authors, the space between the first author’s last name and “and” is missing, so that

J. Smith and M. Jones

is rendered as

J. Smithand M. Jones

If I switch the document from REVTex 4.2 to REVTex 4.1, then the bibliography renders as expected.

I haven’t been able to track down this problem any more deeply — e.g., the console output doesn’t suggest anything obvious — and my internet searches haven’t turned up any other reports on this behavior.

Any suggestions on what I might be missing?