[Evolution] Not marking unread messages read

[Mark Stanton <mark stantoncentral co uk>]

When I open a folder and the currently selected message is unread, it
doesn't get marked as unread after the timeout I've set.

Is this a known bug, a bug at all, or simply showing I've set something
up incorrectly?

This is 3.36.5 (3.36.5-1.fc32) 

Mark
Please don't ask me to upgrade to the latest version (if there is a
later one). This version comes with my Linux repo, which is Fedora 32,
which means it's at least fairly recent.