When clicking the "all changes" diff link in an email notification and being taken to the mobile site (e.g. by clicking the link from a mobile device), if the diff would cover multiple revisions, the diff shown is with the next-older revision instead.

For example:

1. Page "Foobar" has revisions 1, 2, 3, 4, and 5.
2. I last viewed "Foobar" while logged in after revision 3 was saved.
3. I get an email notification for the new edit when revision 4 is saved, and before I check it, revision 5 is also saved.
4. I click the "all changes" link, expecting to get a diff that compares revision 3 (the last one I viewed) and revision 5 (the most recent one)
5. Instead I get a diff that compares revisions 2 and 3.

Note that this also happens if you click the link and view the diff on the desktop version of the site, and then click the "Mobile view" link in the page footer.

Example diff: https://yugipedia.com/index.php?title=Vol.1_(DM5)&diff=0&oldid=4070535
Mobile diff: https://yugipedia.com/wiki/Special:MobileDiff/4070535