Incompatibility with siunitx table column type

[Arkonos]

siunitx 2020/02/25 v2.8b
accessibility 2019/11/02 v. 2.0.3

When I use more than one S column of the siunitx package I get a lot of errors like

Missing } inserted.

Commenting out the accessibility package or using a single S column resolves this issue.

\documentclass{article}  
\usepackage{siunitx}  
%\usepackage{accessibility}  
\begin{document}  
	\begin{tabular}{SSSS}  
		     & 1 &   &      \\
		     &   & 2 &      \\
		3.33 & 3 &   & 11.3 \\
		41.4 &   &   &
	\end{tabular}
\end{document}

Perhaps related to #44.

[AndyClifton]

@Arkonos thanks for this report.

Unfortunately it seems unrelated to #44 because I can fix #44 but that doesn't change anything here.

I've added this as a unit test but I suspect that this will be a hard one to fix as its driven by what goes on in siunitx.