I am not sure if you can access this text file with some more commands, let me know if not.

Still, I'm going to post my further findings and results to anyone who may run across something similar and find this forum post, trying to solve it yourself

I moved the OWC enclosure back to the first server, formatted as NTFS, and had surprisingly good results. Around 900-1000MB/s both read and write, using the same test that had previously reported only 40MB/s for both. I tested a few more times and it was consistent, so I reformatted to ReFS and tried again. Not quite as fast, but close, reporting read in the 900-1000MB/s range and write around 750MB/s.

No idea why I had such trouble to start, but the speeds now are very good. There is still the issue with restarting while the device is active and connected. Unless anyone has an idea about that, I'll wait for a response to it in my support ticket

You should open a support case for this issue, so it can get the attention it deserves.

• Do you have a Pi-hole, pfSense, AdGuard Home, or any similar network-level filter on your network?
• In the terminal.app, run: systemextensionsctl list - Save this as a text file as before, so we can check if there is  anything active you may have forgotten about.
• Also in terminal: profiles list   -  Save this as a text file also.
  Attach the two files. I think we can track down the root cause of this soon.

Now I need to move it back to the original computer and test again, which I can't do until tomorrow. It could be that ReFS is indeed the issue, which I'm leaning towards since I couldn't even change the format to ReFS on the 2nd computer. It could also be some other incompatibility with the USB-C hardware on the first computer too, but being that I have other external devices running at normal speeds on that computer that seems less likely. I'll report findings once I've ran that test.

Let me check with the store admin first. If there is a charge, we could refund it. But there should not be, from what I can see.