DISK NOT EJECTED PROPERLY keeps popping up Big Sur 11.3.1

Finally! The following worked for me I am running macOS Montery 12.3.1 on the base version of Mac Studio.  My situation: This eject thing was happening to me repeatedly sitting idle as well as running a production php to process videos and photosets for release on my website.  This program can take 10 to 30 and more minutes easily depending on how many videos and photosets I process. I have an older Fideco docking station that had been hooked up to my 2013 iMac.  In this dock I have a 10TB hard drive and a 480mb SSD. This particular dock uses USB A to connect to the CPU.  I need to use a USB extension cable because the docking station can not reach either the the Mac Studio or iMac based on my placement of stuff on my desk. So, I connected the extended USB A cable from the Fideco dock to a USB A slot on the back of my new Mac Studio.  I would run my production program and EVERY single time I would get disk eject msgs for each volume stored on the Fideco dock.  I would even get the eject msg with computer idle.  My solution: I read the comments on this thread how it might be a power issue.  So what I tried that is still working with NO eject msgs is: 1) Attached the extended male USB A from the docking station into a short USB A to USB C Apple cable.  2) plug the Apple cable into a USB C slot on the back side of the Mac Studio.  3) In the System Energy Saver prefs I checked “Prevent your Mac from automatically sleeping…” and unchecked “Put hard disks to sleep when possible”.  Aside from the preference settings, I suspect it was the connection from my dock via USB A to USB A that was the problem (perhaps also the use of the extension cable).  Just finished another run of my program — took 40 minutes.  Also took 10 minutes or so to write this text.  Still, no eject msgs! Still use the original USB A cable and extension. Now, however, I plug the USB A into the short Apple USB A to USB C cable and then the USB C into the back of my cpu.

I have the same problem but it appears to be a mechanical issue. The plug, if jostled even a little, will lose the connection to my Mac. Is there a clamp that can be used to hold the plug in place? Smallrig makes one but they appear to be overkill. Any suggestions?

I wish apple would WAKE UP AND ADDRESS THIS ISSUE - external hard drives ejecting themselves, this is NOT ok - It's happening a dozen times a day, however NOT perfectly repeatable. I thought it was my cables, my usb connections... nope, it's Mac OS... After over 30 years being fiercely loyal to only working on macs, I am ready to completely abandon mac and go PC.

This is happening to me too and is causing a huge problem for me as a photographer -- I keep all my photographs on an external 5Tb Seagate drive, and when I'm running Lightroom, having the disc spontaneously "improperly ejected" really wreaks havoc in my lightroom catalogs. It only happens on my new MacBook Pro laptop running Monterrey and NEVER happens with the same hard drive on the iMac running Big Sur.

I just purchased a Lacie 5TB portable drive. I thought initially that it might just be the brand, as I have several removable drives connected to my iMac and I do not have this problem. I did reformat my drive to MacOS Journaled. This may be part of the issue. I will reformat to exfat and see if that helps with the issue.

Do our external backup drives have to be APFS to be compatible?

MacBook Air Monterey, had this issue of ejecting drives while trying to get a Time Machine back up done. Tried many suggestions here, nothing worked. Used disk utility to change my Seagate 1TB external to APFS and now I don't get the disk eject error. Note it backs up much faster now. I'm no where near knowledgeable on these issues just sharing what worked.

I am having this issue (with MacBook Air 2020 M1/Monterey 12.4). I have 2014 and a 2018 MacBook Airs and have never had this issue with either of them (and still don't...). I periodically connect my Seagate 1TB External Hard Drive to manually run back-ups - never had this issue until I got the 2020 MBA. AS I TYPE THIS, I am backing up my 2014 MBA to the SAME Seagate that I just spent the last three hours trying to back-up my 2020 MBA to, with no success (every time the new one prepares to run a backup, it ejects - cancelling the backup....but the external hard drive is still visible in Finder. This actually makes no sense. I bought a new cord, thinking that was the issue. No luck. Tried using an Apple adapter to connect hard drive to MBA. No luck. (And my original cord still works to backup my older MBAs). Ran First Aid; reformatted external hard drive; changed power settings....tried everything. No luck. Would really like to hear if anyone has found a solution that works for the 2020 MBA with M1.

Upgraded to Monterey a month ago and started seeing this issue with my G-Technology external disk used for Time Machine (I've been using that for over 4 years w/o problem). Extremely frustrating and quite scary to contemplate losing years of backups. Changing the usb cable and power supply to the external disk didn't solve the problem so finally had to buy a used 5th Gen Apple Time Capsule to use for backups. That's thankfully working fine but Apple really need to resolve this bug. With every major MacOS upgrade, Apple take a few steps forward but break critical features in the process.