Issue 1
- Set modern Vector (skinversion 2) as default
- Go to any wiki page
- Add {{Special:PrefixIndex/pagename/}}
- Save
The interface will switch to Legacy Vector.
The interface will switch to Legacy Vector.
Transclusion of other special pages (e.g. {{Special:RecentChanges/5}}, see https://en.wikipedia.org/w/index.php?&oldid=996380692) also causes this issue.
Also noticing the following:
This seems to be not specific to Vector but default skin, and it's probably a core issue per T269860