After suspend&resume the keyboard layout settings sometimes get reset from "de"&"ru" to "us" as the only layout (and all other settings reset to none). In the keyboard configuration the flag "Use system defaults" is activated (if not, the settings get lost _every_ suspend&resume). It seems to be related to https://bugzilla.xfce.org/show_bug.cgi?id=6109 with the only difference that the problems never appear on login but sometimes on suspend&resume. See also https://bbs.archlinux.org/viewtopic.php?pid=1040567 for further information.
Possibly the same bug has been reported to Ubuntu: https://bugs.launchpad.net/xkb/+bug/944468
Should be fixed in git master branch, feel free to reopen if you can still reproduce.
Thanks for the fix! Unfortunately I've completely changed my hardware (from nvidia to catalyst), so I'm unable to make further testing - with the new hardware the problem did never appear at all. But I'll report in the linked forum topic and maybe somebody else who was hit by the problem can make some testing.
In the Arch Forums the issue has been reported as solved: https://bbs.archlinux.org/viewtopic.php?pid=1166677#p1166677