Rewind button does not save

Hey, I’m trying to bind rewind to a controller button, but everytime I save the core configuration the binding is deleted. How can I bind it permanently to a button? Per core is prefered, but I’ll live if I can bind it to a button for every core.

Per-core hotkeys aren’t a thing, unfortunately (at least not through the menus; you can manually add the line[s] to an override, but inputs are “invisible” to the override system, so if you update the override later, it’ll wipe your manually-added options).

If you want to map it globally, do it without any cores loaded, then quit RetroArch and reopen it (this will force it to be written to the config right then).