Big Sur Disconnecting External Drives on Mac Studio?

No, I have a loaded Studio Ultra and can't keep a drive that was- for years- steadily connected to the Intel iMac it replaces. It is my Media drive where I store home movies, movies, tv shows and I'm lucky to keep it connected for a few hours at most.

What I've already tried:

• 2 new separate cables
• both USB jacks on the Studio
• putting a reliable hub between and hooking it to the hub
• hooking it to a USB jack in the monitor
• attaching, manually ejecting, rebooting, attaching
• attaching, manually ejecting, shutting down, attaching, rebooting
• Firing back up the old Intel iMac running 10.13.6 and plugging it and same cable into a USB jack and leaving it for 2 days. Steadily, consistently attached as expected... exactly as I want it to work with the new Studio.

Conclusion: there are NO solutions. This appears to be a Monterey thing... though there are lots of posts from Big Sur people too.

The last thing I can easily try: I've ordered a USB-C to USB-B cable to see if maybe a spare Thunderbolt/USB-C jack will consistently maintain a connection. I'm doubting it but it's something I can try.

The thing I don't want to try: reformat with Monterey, reload all of the file and see if maybe that does anything. It's already APFS and has been for a few years and I've already run First Aid in Disc Utility several times: no issues.

Mac Studio (or Monterey) just don't want to stay connected with a reliable hard drive that connects just fine with Intel Macs.

I'm open to ANY other suggestions.

Thank you for the suggestion.

Yes, I've tried that one, and also toggled "put hard disks to sleep" (both ways). Sleep definitely seems to be a trigger for a disconnect but even "prevent computer from sleeping" doesn't stop it (and I wouldn't want to leave it that way if it did). It will also disconnect if I connect it and then consistently use the Studio for several hours so I know for sure that it never manages to sleep.

Yesterday I was importing some camcorder raw footage stored on it to convert to prores files on the Studios SSD to edit in FCPX. After some of those imports (but before others) it would unexpectedly eject. Once it did that WHILE importing one of the files.

I've compared relevant settings from old Intel Mac vs. new Mac Studio to see if maybe something else was set differently on that Intel Mac that might have something to do with this. I don't see ANYTHING else to test... but open to suggestion.

For this Studio, I did NOT use migration assistant but full clean install... manually reinstalling the apps I use to keep this Studio as clean as possible vs. bringing over years of accumulated kludge.

All I'm left with is questioning Monterey or questioning (but doubting) the Studios USB-A ports (I tried it on BOTH of those). The one last thing I can still test on my own guesses is a test of USB-C ports vs. USB-A ports. So that USB-C to USB-B cable arrives in a few days and I'll basically switch the connection to a free USB-C/Thunderbolt 4 port. I doubt it will work but at least I can try vs. waiting for maybe Apple to debug USB jack connections. I hope it won't be having to wait for the next macOS version to get real hope for a fix.

For the most part, I've ruled out the external drive itself by hooking it back up to the Intel iMac with the same cable and it maintaining a stable connection. I've also now tried a second powered hub connection (Studio to hub, hub to external drive) but same result.

The only other tidbits that might be worth mentioning are these two:

• it's a RAID-0 setup (2 drives) instead of a single drive external. But again, no prob on an Intel iMac running 10.13.6 using the same cable.
• when it surprise ejects, disc icon disappears and the notification appears warning me about ejecting. Finder and Disk Utility will no longer "see" the drive as is typical of an ejected drive. However, when I then put the Studio to sleep or shut it down, the external makes a sound that typically means it is going to sleep. So it's like there is still some connection to it that can trigger a sound that sounds like the drive is going to sleep when the Studio is put to sleep. On Studio wake, nothing happens with the drive. The only way to make it show again is turn it off, wait a little while, turn it back on.

I've tried to keep considering drive/enclosure, even doing a power down, unplug for a few minutes, power back up. Nothing works.

If anyone has any other suggestions, I'm all ears. I'd really love to have a functional external working with this "latest-greatest" Mac sooner than later.

Thank you both for additional replies. As Al posts, I don't want to have to play some game of consumer roulette trying to luckily find the right new box to buy that may work. I really want the U in USB to apply. This new Mac costs over $6K and is considered "latest-greatest." Of all things that could be wrong with a first-gen device, I would think a standard that has existed for what- 20 years now- should be well implemented and thoroughly debugged by this point.

As one more experiment that I could control myself, I fired up my OLDEST intel Mac- a 2010 iMac and hooked this drive and the same cable to it. After 16 hours, the connection has been stable. I then moved it back to the new Studio, plugged it in and it randomly ejected while I used it- no Studio sleep for sure- after about 40 minutes.

Other things I've now also tried:

• the terminal app option using a sudo command to change disk sleep from 10 to the maximum number.
• a THIRD cable just in case I happened to have 2 bad ones (even though the one has worked and continues to work fine with Intel Mac connections)
• every combination of Power Saver options. However this is also happening without letting Studio sleep (active use) and even while pulling files from this external so that it can't be asleep (put drives to sleep when possible) either.
• Submitting a bug report to through the macOS support form for bug reporting.

The last things that I can actually try myself unless anyone has any other suggestions:

• Awaiting a USB-C to USB-B cable to arrive in a few days. This will test if maybe the USB-C jacks are more stable than the USB-A jacks on the Studio for this connection.
• Reformat the RAID with Monterey Disk Utility even though First Aid says all is fine. I don't want to do this one because the amount of files is large (over 15TB) and I feel that all that will happen here is I'll find myself hooking it plus a backup back to an Intel Mac so I can reliably reload it with all those files without random ejections.

This can't be a MAJOR problem, else the noise about it would be louder. Searches seem to find LOTS of people do experience this, especially since Big Sur. Of all things that could be wrong with the new Studio, I really wish this was not one of them. Didn't the original iMacs come with USB jacks??? It seems USB on Apple hardware should be completely debugged by now.

I had this issue on my Mac Mini M1 with Monterey. After trying different drives and cables with no luck I replaced my drive with a Thunderbolt drive (NVME in a Trebleet enclosure) and no more disconnects.

As a bit of followup to this thread, the USB-C to USB-B cable arrived. Hooked it up and same result. So basically for this 2018-purchased external, 2-drive RAID box, no stable connection whether hooked to USB-A or USB-C on the brand new Studio Ultra. It has worked fine hooked to Intel iMacs for the last couple of years and will work fine re-attached to Intel Macs but can't keep a stable connection to Studio.

Hopefully, Apple will squash whatever bug(s) is in play here sooner or later.

FYI, I also had no issue with any drive on my other Macs not running Monterey so I believe it could some OS issue with certain drives.

I also had tried several different cables and drives and enclosures. Very frustrating.