In FreeBSD, dvipdfmx and xdvi use libpaper which is not support JIS B series paper size, which is one of the standard paper size series. JIS B is like a ISO B series, but not the same. cf. https://en.wikipedia.org/wiki/Paper_size#Japanese_B-series_variant The attached patch may fix the problem. If it not allow to add the patch in print/libpaper, I hope making japanese/libpaper to use the patch.
Created attachment 197046 [details] a patch for print/libpaper to enable JIS B series paper size
Hi, Sorry for the late reply but does this fix your issue? Best regards, Daniel
Closing this due to submitter timeout