I am using Mint-Xfce, so I am not 100% sure whether to report here or to Mint.
The problem is that each time I reinstall system I have days of pain, editing shortcuts to Xfce and Xfwm is just that.

These kinds of problem arise:

-- removing keyboard shortcuts usually does not work, the button just does nothing. Not even warns you, just does nothing.
-- Editing a shortcut does not activate new mapping, although it is shown in a list as edited.
-- Clicking OK in "edit shortcut" sometimes (often) changes the shortcut, but if you restart the shortcut editor, the shortcut  isunmodified, i.e. back to previous state.
-- Successfully edited shortcut often works only until you restart, or sometimes just a few hours, and goes back to previous action without any reason that I am aware of.
-- Modifying the shortcuts in the .xml files often will not have any effect. Deleted shortcuts still work, added do not work, modified keep previous action. And it is also inconsistent, because sometimes the entered value will just work.

I would come up with something more technical like steps-to reproduce, but
1) it would be real hard, because the behavior is not consistent and I would need to reinstall whole system to have the same initial state.
2) the whole keyboard shortcut editing system is so faulty that it should be visible to any developer that it needs a major refactoring. You just install the thing and it does not work out of the box. It is just so obvious.

I see you have a lot of similar bug reports, and they are marked FIXED. But I still file this bug, because I see no progress in this regard in the last few years.

I believe the logic of config-chaining is totally broken, the editors (both Settings->Keyboard and Settings->Window Manager->Keyboard) seems to me, do not follow the same logic as the keyboard shortcut handling module does.

Maybe config files actual permissions are not taken into account.

Thank you.