After copying https://www.mediawiki.org/wiki/Extension%3AStructuredDiscussions#Enabling_or_disabling_StructuredDiscussions into a VE editor in SD, it is correctly detected as an internal link and the text is right.
However, the link becomes https://www.mediawiki.org/wiki/Extension%3AStructuredDiscussions#Enabling%20or%20disabling%20StructuredDiscussions , which does not open to the section.