F8 clearing the name is a feature of Byobu.
ctrl-a-A is screen's hotkey, and if you use it, you get whatever screen
does with that keybinding. In your case, it allows you to change the
name of the window, without clearing it.
This isn't a bug in Byobu. You could perhaps ask screen to change thi
** Attachment added: "Binaries.txt"
http://launchpadlibrarian.net/35858007/Binaries.txt
** Attachment added: "Dependencies.txt"
http://launchpadlibrarian.net/35858009/Dependencies.txt
** Attachment added: "RelatedPackageVersions.txt"
http://launchpadlibrarian.net/35858011/RelatedPackage