Steps to reproduce:
- Open https://commons.wikimedia.org/wiki/Numbers
- Click the first image, click on to the next image, until you reach 10.
- Close the media viewer.
- Repeat step 2.
Expected result: You still get images 1, 2, 3, ..., 10
Actual result: You get 1, 3, 5, 7, 9; repeating this, the next time you get 1, 4, 7, 10; 1, 5, 9 etc.