Expected:
The display of a horizontal line in the footer of a page in the Page namespace.

Current status:
The line is not visible.

To Test:
This was tested in Windows 10 64bit, with Firefox Quantum 64.0, and then trying to replicate the results in Vivaldi as well.

Tried using Vivaldi 2.3.1401.7 Official Build, but currently this is not possible because of the bug reported in T212999, so please use Firefox.

Open browser to this link. https://en.wikisource.org/wiki/Page:Houses_and_House-Life_of_the_American_Aborigines.djvu/317.

The page appears is 'Read' mode.

This page has a reference in the footer.

Scroll down to the end of page where the reference is displayed.

There should be a horizontal line above the reference.

Click 'Edit' to see the contents in text mode.

Scroll down to the end, and click the [Show Preview] button.

The horizontal line shows up in 'Preview' mode but not in 'Read' mode.

{{rule}} is the wikisource template which draws the line.

Comparison test.

Replace the {{rule}} with the HTML <hr> and this shows up in both 'Preview' and 'Read' mode.