paragraph breaks in tikz figures cause errors with linenumbers

[darthoctopus]

Minimum working example:

\documentclass[linenumbers]{aastex631}
\usepackage[utf8]{inputenc}
\usepackage{tikz}

\begin{document}
\begin{tikzpicture}[xscale=1.2, yscale=1.2]


\node at (0, 1){1};
\end{tikzpicture}
\end{document}

This yields compile errors whose source is nonobvious:

/home/joel/test.tex:8: Improper \prevdepth. []
/home/joel/test.tex:8: You can't use `\prevdepth' in restricted horizontal mode. []
/home/joel/test.tex:8: Missing $ inserted. []
/home/joel/test.tex:8: Missing number, treated as zero. []
/home/joel/test.tex:8: Illegal unit of measure (pt inserted). []
/home/joel/test.tex:9: Missing $ inserted. []
/home/joel/test.tex:9: Improper \prevdepth. []
/home/joel/test.tex:9: You can't use `\prevdepth' in restricted horizontal mode. []
/home/joel/test.tex:9: Missing $ inserted. []
/home/joel/test.tex:9: Missing number, treated as zero. []
/home/joel/test.tex:9: Illegal unit of measure (pt inserted). []
/home/joel/test.tex:11: Missing $ inserted. [\end{tikzpicture}]

Removing the empty linebreaks before defining the \node resolves the compile errors.