The "Contents" table does not follow the displayed page content

If a page is quite long and the Contents table is longer than a single screen, when a user scrolls down through the page, the table is stuck at its top and moves down only when the end of the page is reached.

STEPS:

1. Use FireFox or Edge and open one of the following pages:

• https://doc.qt.io/qt-6/12-0-qdoc-commands-miscellaneous.html
• https://doc.qt.io/squish/squish-api.html

1. Scroll down a bit, untill Contents stops moving
2. Click the last visible link in the "Contents" table. (In my case, for the first link, it is \meta)
3. Scroll down the page

EXPECTED:
The visible part of the content table should follow the content of the page so I can see the exact position I'm currently in.

RESULT:
The vibile part of the Contents table stays in place until the end of the document is reached. Only then I can see the bottom of the table.