OWC Envoy Express Causing Speed Problem With Other Drives

Setting up and testing my new (refurbed) base Mac Mini M2 Pro I ran across a head scratcher that appears to point to the OWC enclosure as the culprit.
I have two Acasis TBU405 enclosures each with a 2TB Samsung 970 EVO. The OWC has a Silicon Power 2TB. My plan was to use the SP NVME in the OWC as my home/user folder. One of the Samsungs will be my Final Cut Pro work disk and the other will house my photo and video archives.
Moving the home directory to the OWC worked flawlessly. Before calling it a night I decided to test the speeds of the drives with Black Magic. The one 970 was as expected, 2800 write and 2730 read. The other drive was below 1000 for both read and write. Bum enclosure? Bum drive?
If I only ran one Acasis/Samsung drive at a time with the OWC also plugged in each had full speed.
No matter which drive I selected the first one was full speed and the second one plugged in fell back to below 1000. Which of the four ports I selected did not matter.
I rebooted the computer to disconnect the OWC drive and boot into another user account. You cannot unmount a drive that has been set at the home folder. Both Samsung drives reported the same 2800 write and 2730 read via Black Magic!
Reboot with OWC running and it's back to slow speed for one of the Acasis/Samsung drives if both are mounted.
If I unmount the fast Acasis/Samsung drive the remaining Acasis/Samsung still runs at the slow speeds. If I unmount/unplug the slow drive and plug it back in alone it's back to the full 2800 write and 2730 read speeds.

[@ivahos]

To make the system information list update, you have to either restart it or press command+r.
Also, I suspect that the OCW drive causes one of the drives to be recognized as a USB 3.1 gen 2 drive. Refresh system information, and you will find it under the USB tag instead of the thunderbolt tag.

[@jim0266]

Thanks @ivhos, you are correct! It's being seen as a USB 3.1 gen 2 drive. I have it plugged into my Studio Display. I returned the OWC Envoy Express and went with another Acasis TBU405 since it was the same amount as the OWC and seems like a better enclosure. Getting ~900 MB/s R&W from which is plenty fast for what's stored on this drive. No issues so far with the TBU405's or any of the three NVME's.

[@ivahos]

@@jim0266 the ovc drive is a thunderbolt 3 device. That might have something to do with it