Switching a titlebar button's position works fine, but once you have moved it, it disappears from the settings interface, so you cannot move it anymore unless you close and reopen the settings panel.
Works fine here, please provide the reproduction steps.
Nothing special to do: open the settings panel -> window manager, move titlebar buttons and you will see them disappear (from settings interface, not from titlebar). If you move all of them there will be at the end no single button anymore. This is a Xfce 4.13 problem, in 4.12 it works fine.
I cannot reproduce this bug either. Are you sure that you have version 4.13.2? It includes the fix for bug 14606.
For sure, I'm currently running xfwm 4.13.2 on Mageia 7. I also tried on Fedora (which has 4.13.3) and got the same result.
Created attachment 8811 Disapparing buttons Reproduction of the bug on Xubuntu 19.04 with Xfce testing repository enabled
I can reproduce this bug, Xfce 4.14 on Manjaro Linux 18.0.4. Behavior is identical to the video attached earlier.
After checking again I can confirm that the bug occurs when xfwm4-settings is embedded in the Settings Manager.
I have the same issue with xfwm4-settings 4.14.0 when launched from xfce4-settings-manager 4.14.1 on Fedora 30. Seems to be a duplicate of https://bugzilla.xfce.org/show_bug.cgi?id=13861
*** Bug 16396 has been marked as a duplicate of this bug. ***
*** This bug has been marked as a duplicate of bug 13861 ***