I Have similar trouble with russian layout (us,ru). I found https://bugs.freedesktop.org/show_bug.cgi?id=98495 and reported there similar workaround patch.
--- /usr/share/X11/xkb/symbols/ru.old 2016-11-25 12:11:18.514783863 +0300 +++ /usr/share/X11/xkb/symbols/ru 2016-11-25 12:10:23.734272871 +0300 @@ -20,7 +20,7 @@ key <AB10> { [ period, comma ] }; key <BKSL> { [ backslash, slash ] }; - include "level3(ralt_switch)" +// include "level3(ralt_switch)" }; hidden partial alphanumeric_keys