If you're having problems with USB on macOS Sequoia, you're not alone

AppleInsider

If you're experiencing issues with USB on your Mac after installing macOS Sequoia, you're not alone, with some users reporting drive connectivity issues.

macOS Sequoia with iPhone Mirroring

Following the release of major operating system updates, there are often small issues that crop up that weren't picked up during the beta-testing process. As expected, this has happened to macOS 15 Sequoia, which was released on September 16.

There are a few reports on Reddit and on Apple's support forum claiming that some upgraders to macOS Sequoia are having USB port trouble. Drives and chargers plugged into the USB-C ports of a MacBook aren't being detected, or take a long time to become usable, one Reddit post claims. There are other similar reports on Reddit as well.

Others in the Apple support community discovered that their USB flash drives aren't being recognized. They simply do not appear in Disk Utility at all, meaning they aren't even mountable in the current state.

It appears that the issue isn't limited to a specific model, nor to a chip, with M1, M2, and M3 chips seemingly affected, as are the MacBook Air and iMac.

It is unknown if Apple is aware of the issue. Online reports don't mention any communications with Apple's support teams.

We can't reproduce the problem across any combination of hardware. To date, the issue doesn't appear to be widespread, as there would be much more conversation about the issue if it were.

AppleInsider suggests that affected users should contact Apple Support so that the problem can be acknowledged and a potential software fix worked on for a future update. Apple does not respond or catalog social media reports of problems.



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dewme

I’ve had with USB drives and USB-C hubs disconnecting long before Sequoia, whether or not the hub is powered. I suspect the power and sleep settings affect the behavior but I’ve yet to find a combination that works consistently. It’s not like it happens all the time either. In any case, this randomness has kept me from buying a more expensive super hub because I don’t trust that a $400 USD hub is going to solve the problem, especially when product reviews indicate others having USB disconnect issues on those expensive hubs. 

netrox

I have several USB devices connected to my USB hub to my Macs (both Intel and M). No issues so far. 

dominikhoffmann

I have had an issue for quite some time, possibly since Ventura, where the dialog asking me to allow the USB device to connect disappearing within a fraction of a second. I miss the dialog altogether. My workaround has been to unplug the device and plug it in again, repeatedly in necessary, until I can okay it. From then on I don’t have a problem with the device.

marvin

dominikhoffmann said:

I have had an issue for quite some time, possibly since Ventura, where the dialog asking me to allow the USB device to connect disappearing within a fraction of a second. I miss the dialog altogether. My workaround has been to unplug the device and plug it in again, repeatedly in necessary, until I can okay it. From then on I don’t have a problem with the device.

The confirm dialog disappearing so fast is really badly designed, I don't know how that got past testing. There's a preference in System Settings to avoid manual approval of new devices:

https://support.apple.com/guide/mac-help/allow-accessories-to-connect-mchlf779ae93/mac

Another fix that can sometimes work for drives not mounting is force quitting the diskarbitrationd process and plugging the drive in again.

freeassociate2

Curious if these folks are using sub-standard or incorrect USB cables. It could be that the operating systems (I’ve seen this with Windows 11 as well, particularly company managed units) have become less promiscuous in allowing poor quality cables to function.

Case in point, I have an LG USB-C only monitor I use in testing. No firmware has been updated on the unit, as far as I can tell. And yet, in recent months the newer OS versions stopped working with the original 10Gbps cable, then all 10/20Gbps cables I have. And now only works with 40Gbps USB-C cables. The caveat here is this is the only USB-C PD unit I have. However, anecdotally, I have noticed similar issues with all equipment, particularly hubs, and across multiple different machines. (I’m discounting Linux-based OSes here as they’ve always been persnickety.)

I source my daily-driver cables from reputable companies known for quality products, but also have dozens of no-name/no-spec cables that were included with various products. These seem hit-or-miss in their functionality.

All of this is just personal experience, mind you. I have no hard evidence that points to any one thing in particular other than I’ve had to swap out a lot of cables.

On that note, I’ll point out that I don’t have access to a cable tester. But if someone wants to make a recommendation, that would be appreciated. 

edited September 2024

commentzilla

There is no mention of a dock in the article. But problems with docks is a real issue. I have a Caldigit and a OWC Thunderbolt dock and they do not randomly disconnect drives, but they do disconnect under very long sustained read operations. This at first appeared to only occur with SSD drives but if you have a very large HDD, it will also occur under long read operations. With SSDs the failure happens faster than HDD drives because they transfer data faster. I suspect this has something to do with power management, even if the drive is self-powered. None of this happens if the drives are connected directly to the Mac. It only happens when the drives are connected through a dock.

edited September 2024

poisednoise

I'm having serious issues with USB - hard drives dropping, sound DAC disconnecting, USB microphone not working. A lot of these are connected through USB hubs, but not all by any means.
iMac 27-inch, 2020

docfun

After today's Sequoia update:  My USB would not charge iPhone but a hard re-boot worked.  My Time Machine would not mount on desktop and it kept coming up with "backup failed". I went to "Browse Backups" and it went to that.  After about 30 seconds it showed the backup dates with the window choices.  I waited a bit longer and then exited.  The backup disk had mounted and it was doing a backup.  Hopefully this works for others.

tanbrae

First, apparently this IS a known issue by Apple. I didn't have an issue with externals until "upgrading" to Sequoia. When I looked for a resolution, I found this:  https://discussions.apple.com/thread/255776197

I have a 2023 Studio M2 Max with 32 GB memory. Things were working fine with all externals until Sequoia. Because of my work, I need to use multiple flash drives at the same time. Apple, in their infinite wisdom, has chosen to not add enough ports, AND, on the Studio, the USB ports are in the BACK of the machine. Not very accessible, especially when I need to connect and disconnect multiple, multiple times. So, I bought a powered hub - one that was highly recommended for Macs. It worked well. Until Sequoia. It's no longer recognized. 

Let's add to this issue. My husband has a pacemaker that requires a monitor. That monitor uses a USB 3 connector. That means that one of my ports is being used by that monitor. As the Insignia is no longer recognized, I don't have the option to plug the pacemaker monitor into it. 

Was just chatting with Apple "help". Explained the whole situation, then was recommended to purchase a new hub. So, let's add insult to injury, and recommend a $140.00 hub. Yeah. MORE money. (I just hope my husband is worth it! )

I just don't understand why Apple won't fix this known issue.