This problem seems to resemble the one mentioned in https://www.mail-archive.com/pdl-porters@jach.hawaii.edu/msg03022.html. If so, it was fixed in PDL 2.4.8.

I've also added a test in https://github.com/PDLPorters/pdl/commit/8a947b0b118ff6c1f291953779f4efd36631bb0b just to permanently ensure this doesn't happen again.