I am writing a multilingual document and want bibliography entries properly hyphenated for their language. I do not want to translate terms in the bibliography like "in", "p.", and "edited by". As I read the BibLaTeX documentation, autolang=hyphen should do this, and it seems to me that it worked in the past, but now it also causes the translation of terms used in the bibliography, like "pp." to "S." for a German entry, which is what I would expect from autolang=other. Here's a MWE:
\documentclass[a4paper]{article}
\usepackage{polyglossia}
\setdefaultlanguage[variant=american]{english}
\setotherlanguage{german}
\usepackage{csquotes}
\usepackage[style=verbose-ibid,autolang=hyphen,backend=biber]{biblatex}
\addbibresource{biblatex-examples.bib}
\begin{document}
Here I cite Sigfridsson\autocite{sigfridsson} and Spiegelberg\autocite{spiegelberg}.
\printbibliography
\end{document}
The example bibliography entries use langid to specify the language ("american" and "german" respectively). I get this (with similar results in the footnotes):
Update: since the problem was identified as a bug, I add some version numbers in case anyone reads this in the future: BibLaTeX 3.7, Polyglossia 1.42.4.

polygossiasupport is shaky it best. If you don't need any ofpolyglossia's special features you might be better of usingbabelinstead. – moewe Apr 19 '17 at 17:18polyglossiabecause I understood that it should be used instead ofbabelwith XeLaTeX. Am I mistaken? Since the primary language is English, all I really want frombabelorpolyglossiais hyphenation: I don't need translations of dates or terms used by LaTeX. – jcr Apr 20 '17 at 17:54polyglossia. I have not that much experience withpolyglossia/babelon Xe/LuaLaTeX, but I'm lead to believe that even though generallypolyglossiais 'preferred' sometimesbabelis good enough (cfbabelvs.polyglossia). – moewe Apr 21 '17 at 06:40