Looks very similar to the issue I had with xfwm4. Also a wrong vertical alignment. Here is a link to the bug reports in upstream's tracker: https://bugzilla.xfce.org/show_bug.cgi?id=16067
Recently, upstream fixed the issue. Also, xfwm4 version 4.14.1 was released that have the issue fixed. Try to install xfwm4 4.14.1 when it becomes packaged. Or try to build xfwm4 from source. --- Rinat