External drive NVME SSD, random ejection, I thought I fixed the issue. it's the MBP :(

Hello all! Long time reader, first time poster. Anyway, I have been following this issue for the past week as I have run into the same issue with my brand new custom NVMe drive unmounting randomly from my MacBook Pro with touchbar intel i9. I am not as tech savvy as many of you, but I am good at troubleshooting given a long background working with Mac and other tech support positions.

the issue I noticed with two different enclosures- Yottamaster and Sabrent, the latter being the enclosure recommended by the drive manufacturer in emails I sent before starting my build, is voltage drop. My technique was basic. I watched the blue light each time since the issue happened within the first 3 minutes of mounting the drive. The blue light faded ever so slightly right before the issue happened.

I had already run through two enclosures, different connectors, and different USB-C ports, of the 4 available. All still had the same issue: blue light dimmed right before the improper unmounting of the drive. I am set to return everything and just go back to building SATA SSD drives when I remembered one more option. I have the DockCase brand docking station. I am currently using the 7-in-1. This case lets me customize its setup (on windows only) with power draw and the visual screen built in, not a sales pitch I just think it is cool.

BUT!

it worked. The DockCase stabilized the power draw from how I interpret the issue and it is no longer improperly unmounting. My limit before was about 22GB transferred before it would unmount and now it stays on. This really adds another cable but I am going to try their NVMe case as it contains something that no other single NVMe case had that I have seen, a capacitor to provide 5 or 10 second, depending on the case I get, emergency power backup in case of a power issue. I believe this EDLC is the key to making sure the power to the enclosure stays constant as well.

I will update further once the enclosure arrives. But for now, going through my DockCase has fixed the unmounting issue and the only drawback with the model I have is that it is a 5gbps limit on the transfer speed due to the usb 3.0 which I will be updating my case to the newer model to increase to the 10GbpS.

too bad with all the money spent on a MBP, the issue even happens at all.

UPDATE:

sorry for the long delay. Life got in the way. in a bad way.

My Dockcase readings proved there is an unstable voltage issue on the 2019-2020 Intel MBP in the USB-C ports. voltage fluctuates at random from 4.85 volt up to 5.27 volts with a mean running voltage level of 5.12 volts. the NVMe needs minimum of 5 volts to operate to avoid the unmanning issue which then causes an improper disconnect issue, about 127 times now according to the Dockcase which also showed a graph readout on its screen of the voltage flutter. only a handful of times has the NVMe worked while plugged in directly to the USB-c. the drive isn't going to sleep as I made sure that option was deactivated in the mfgr software, and it works fine on my other non-Apple laptop, but due to what I built this for it needs to run on the MBP. To otherwise guarantee its stable operation running the NVMe Dockcase enclosure through the 9-in-1 or even the 7-in-1 Dockcase dock is the only safe way to run it due to their design and power handling. they also monitor temp settings and it stays in a nominal range around 123 degrees at the highest. I used a high quality heat sink with it to better dissipate the heat and all new high quality cables designed for the job by the mfgr that ha always worked great.

I did see a couple of good suggestions in the original post except dealing with Apple Support on past technical issues bore no solutions to my very "...interesting and unique issues..." at those times.

I will also mention that aside from the NVMe enclosure and drive and the Dockcase brand the MBP and its power supply are the supplied apple accessories the came with the new MBP. the NVME does require more juice than my other non-NVMe drives both solid state and HDD external drives.