\setmathfont affects the scaling of math fonts defined earlier

[gadmm]

In the following example, the size of \mathscr{D} changes if the commented line is uncommented.

\documentclass{article}
\usepackage{fontspec}
\setmainfont{Latin Modern Roman}
\usepackage{unicode-math}
\setmathfont{Latin Modern Math}
\setmathfont[range={\mathscr},Scale=MatchUppercase]{xits-math.otf}
%\setmathfont[range={\rightarrow},Scale=MatchLowercase]{xits-math.otf}
\begin{document}
\[
D\mathscr{D}
\]
\end{document}

Unicode-math version 2015/09/24 v0.8c.