One possibility might be that the KVM is presenting itself as a keyboard that is constantly connected, rather than the actual keyboard. If the USB HID descriptor of the KVM and/or vendor id doesn't match the way the special keys are implemented on the actual keyboard, they might end up not working. Apple's media keys nowadays are just using the keycodes of F1–F12 + Print Screen / Scroll Lock / Pause/Break, so one thing you could try is just use those, and turn off the setting to use function keys as function keys in System Preferences (it is off by default).jamesborr wrote: ↑24 Sep 2022, 06:48As I am running the keyboard on mostly Mac's, I was hoping to leverage a couple of keys for media functions (Mute, Volume +/-), and so purchased a set of media keys and configured them in VIA -- and they work perfectly when I connect the keyboard to a computer directly or via a USB hub -- yea!. Now for the wrinkle -- these same media keys do not function when I connect the keyboard to the keyboard control port on my KVM (ioGear GCS1794). I am aware of the potential idiosyncrasies associated with "special" keys and KVM's, however, I have 2 other keyboards (Wired Apple and a Unicomp for Mac) for which the media keys do get passed and function properly through the keyboard control port on the KVM.
A more advanced way to do this is to compile a custom firmware using Apple's USB vendor id and the product id of the Apple keyboard most closely matching yours. As a bonus, you can have a real Apple Fn key if you do this (it is not possible otherwise, as it uses a vendor-specific extension page in the HID descriptor). This requires patching the firmware, though, and maybe also the VIA tools if you wish to use it (but if you're building custom firmware, you might as well just use the QMK web configurator and skip VIA). (I can elaborate if you wish to go down this road.)