"Automatically sync when this iPhone is connected" doesn't always work on macOS Tahoe

Keith Riggle wrote:

"Automatically sync when this iPhone is connected" doesn't always work on macOS Tahoe with iPhone running iOS 26 connected via USB

Apple suggests connecting DIRECTLY to the Mac to sync an iPhone. You aren't doing that. I don't know how often you need to sync the iPhone. If it's not very often, why not simply unmount a drive that is using one of your Mac ports so you can connect the iPhone directly as Apple instructs.

Any suggestions on how to get it to work consistently ...

Look into getting a hub that works properly.

I have been using OWC Thunderbolt hubs for some years now, both for my work and personal Macs (these are Macbook Pros). I typically will have two or three external drives connected through those OWC hubs and have never had to connect them directly to the Macs. I avoid connecting drives directly to the Mac because that would mean constantly having to unplug them when taking the laptop somewhere. The hub makes this much easier, and OWC also provides a little utility called OWC Dock Ejector that when clicked simply dismounts properly all the drives that are connected via the hub, so one can take the laptop for portable use. The Macs (and presumably the drives) periodically sleep and wake up with no issues. This leaves other ports on the Mac available for other things, including iPhone syncs. That said, I have also synced my iPhone through these OWC hubs. Never with any issues. A properly designed hub will being able to host multiple drives and sync the iPhone as well, although I do usually follow Apple's guidance on syncing the iPhone through a direct cable. l

Just another example of an Apple feature that does not work as advertised.

Except you didn't follow Apple's guidance on using a direct connection for the iPhone sync. And your hub is clearly not fully compatible with macOS, what hub are you using.

I use the ports on my Mac for important external drives, which obviously don't work as well through the hub.

That sounds odd. My ancient Thunderbolt 3 hub provides 40 Gbps. You need a modern hub, I think. OWC's Thunderbolt 4 hub provides three 40 Gbps ports. The Thunderbolt 5 version provides 80 Gbps. These OWC hubs also provide pass through charging (140W for the latest version). You can connect everything via these hubs using just one Mac port. The OWC Dock Ejector menu item provides a one click orderly dismount of all connected drives in one click. Disconnect one cable and you can take the laptop off for portable use.

I agree with Martin R. regarding "lazy" USB sockets. I always plug my phones and iPad directly into my Mac and sometimes, particularly on one of the ports, it doesn't recognize that the device is attached. I normally run Activity Monitor and kill the usbmuxd and AMPDeviceDiscoveryAgent processes (they restart automatically so don't keep killing them when they reappear) which usually kicks off discovery. Sometimes I have to unplug and plug the device back in after doing it . It's a pain but quicker than rebooting.

I also think that having a hub isn't helping you. If killing the processes doesn't help then try again without the hub.

Synching over wifi hasn't worked for me for a long, long time.

Keith Riggle wrote:

"Automatically sync when this iPhone is connected" doesn't always work on macOS Tahoe with iPhone running iOS 26 connected via USB, even when I open the iPhone. It does connect through a USB hub,

Connect your iPhone directly to your Mac to verify that it syncs when directly connected. If that's the case then the problem is the hub.

The hub itself may not actually be bad, just not quite 'awake enough' when you connect your iPhone to it. You said sometimes it works when you restart your Mac ... that action repowers the USB bus, which may be what the hub needs to complete the connection with your iPhone.

FWIW, Apple's instructions are to "connect your device using a USB or USB-C cable or a Wi-Fi connection" which implies a direct cable connection or a WiFi connection between the iPhone and the Mac. See Sync content between your Mac and iPhone, iPad, or iPod touch - Apple Support for more information.

So I asked AI, and the usbmuxd daemon manages communication between the Mac and connected iOS devices over USB or Wi-Fi. I went ahead and killed both processes, waited for them to restart, and now I'm getting error messages like, "The iPhone 'Keith's iPhone' cannot be synced because it cannot be found." I restarted the phone and then it synced automatically. So that's better than having to restart the Mac. Next time I'll just try restarting the phone first without killing the processes.

Thanks for the advice, to include the NAS suggestion. I've thought about it before but was too lazy to implement it. Maybe it's time.

The hub is always "awake" when I'm using the Mac because it's connected to an external display, not to mention a USB mouse and external hard drive. The iPhone is always connected via WiFi as well (I get notifications from it), but auto-sync doesn't seem to work with it at all, only with USB.

Thanks for the suggestion.

Killing those processes sounds quicker, but will it disconnect my USB hub (which has external drives connected to it)?

I don't have any choice about using the hub. I use the ports on my Mac for important external drives, which obviously don't work as well through the hub. The ones on the hub are backups that run after hours, so performance isn't as much of an issue.

Keith Riggle wrote:

Killing those processes sounds quicker, but will it disconnect my USB hub (which has external drives connected to it)?

The usbmuxd might - I don't use a hub so can't say with certainty.. The AMPDeviceDiscoveryAgent shouldn't disconnect the hub. It just keeps an eye out for "Apple Media Players". Having said that, I can't test it so I can't give you a definitive answer. However, if you're having to power-cycle your Mac anyway it might be worth a test.

Finally - why not look at setting up a Raspberry Pi as network attached storage. You could attach two discs to it and connect the Raspi over WiFi which might free up some ports. I'm not very tecchie, but when I saw that Time Capsules were to be no longer supported I bought a Raspi and USB drive and it took me less than an hour to set it all up using vids and guides I found on the Raspi Forum. The only downside would be the USB speed between Raspi and discs; it's only USB 3 but the internet seems to think that it's a bit slower than that.

Edit - you might be able to connect your hub to a Raspi - but that you'd have to research for yourself cos I don't know.