\documentclass{article}
\usepackage{tagpdf}
\tagpdfsetup{activate-all,interwordspace=on,
uncompress}
\begin{document}
\tagstructbegin{tag=Document}
\tagstructbegin{tag=P}
\tagmcbegin{tag=P}
Some text
\tagmcend
\tagmcbegin{artifact}
with artifact
\tagmcend
\tagmcbegin{tag=P}
and more content
\tagmcend
\tagstructend
\tagstructend
\end{document}
Stream is ok:
But structure is faulty (MCID 1 is missing):