TOC indent wrong for sect2 entries with xsl-1.68.1

Hi,

I'm trying to migrate from xsl-1.62.0 to xsl-1.68.1 and now the indention 
for TOC's (article) are wrong.

The entries for sect2 titles are indented more left then all other section 
entries.

Also I've tried
<xsl:param name="toc.indent.width" select="25"/>
with no success.

Does anybody have some explanation to this?

Regards,
Alexander