So I’m back with my dual Mac setup. I have an M4Pro mini and a M1 MacBook Pro that are both connected to a KVM built into my monitor. I have an extended keyboard and magic mouse both connected to the KVM via USB cable. The problem is that the Magic Trackpad doesn’t ever seem to know which machine I’m actually using when I switch the KVM.
I solved this by turning off Bluetooth. If I leave Bluetooth turned on, the Magic Trackpad seems to prefer to use that over the plugged in cable. If I turn off Bluetooth on both machines, then it’ll use the cable.
I know this is the edgiest of edge cases, but does anyone know if there is a setting to tell the Magic Trackpad to just use the cable and ignore Bluetooth? I suppose I’d like the same setting to apply to the keyboard as well.
Blame this on the feature that automatically pairs the device when you connect the USB cable. I would expect that if you could run the trackpad through a KVM then at least it would connect to the correct Mac, although it would still be doing it via Bluetooth.
If I try to use my Trackpad via Bluetooth, it’s janky as all heck. Plugging it in directly, it’s rock-solid and reliable. And I switch it back and forth via a KVM. It’s absolutely using the cable for the data connection, pairing, and everything.
This is what mine does. It doesn’t use Bluetooth unless the cable is unplugged.
Have you tried going into the Bluetooth section of System Settings and telling each machine to “forget” the trackpad? If not, if will just keep reconnecting via Bluetooth. Or are you saying that when you plug in the cable, it adds the back the ‘forgotten’ Bluetooth connection?
Hmm. Looking at this some more, while it is plugged in it cannot be disconnected from Bluetooth. I’m concluding that the keyboard and trackpad (and really also the mouse) are designed to be run on Bluetooth all of the time and they only intend the USB connection for charging.
In a way this is consistent with the older AA battery versions of the wireless keyboard, trackpad, and mouse, which of course cannot be used via USB. Note that while I’ve actually got wired, AA wireless, and USB wireless versions of the keyboards and mice (and both wireless versions of the trackpad) I’ve mostly avoided all of this by not using the Apple accessories and just going with old simple wired devices.
Even though that’s what it looks like from the UI, I don’t think that’s actually the case. I think that’s just where it shows up, to let you know it’s plugged in.
Like I said, if I unplug my Trackpad’s USB cable it gets super-janky. The Bluetooth RF interference is insane, due to where the computer is. If I plug it in, there are absolutely zero problems. It has to be using the wire for the computer communication. And of course if I shut Bluetooth completely off, the trackpad keeps working.
Really looks like only two solutions: either find out and solve your RF interference issue or go with other accessories. It appears that the USB cables for the trackpad/mouse/keyboard are really only intended for charging and auto-pairing. Apple stopped selling wired keyboards and mice in 2017 and has never made a wired trackpad. Of course there are plenty of non-Apple, wired alternatives for keyboard and mouse, and frankly better than the Apple products. AFAIK there is no alternative trackpad.
When I connect my Trackpad via USB and then turn Bluetooth off, my Trackpad works just fine.
Furthermore, I have the app Tooth Fairly installed, although I find it of limited usefulness (YMMV). When the trackpad is connected via Bluetooth, Tooth Fairy sees it. When connected via USB, Tooth Fairy does not see it.
Thus I conclude that when connect via USB the Trackpad is not connected via Bluetooth.
Yeah, that’s what I’m seeing too. If I unplug the cable, it’s janky due to RF interference. If I plug in the cable, no problems whatsoever. It has to be using the cable for data/pairing/everything when it’s plugged in.