USB Drive Mount Not in Host OS X

I do not share between the host OS X and the VM OS X. I have told Parallels to ask me what to do when a new device is connected. However, when I plug in a particular USB drive, it is always mounted on the host OS X image. How do I change this so it is mounted on the VM OS X image?

 

Did you try the steps below:
1. Parallels Desktop tab -> preferences -> devices
2. Choose "connect it to the active virtual machine" - > restart VM

 

Thanks, Maria.

I did. I tried all the combinations I could think of. I want to keep my VM OS X isolated, but I violated that restriction to try the following:
- I shutdown VM OS X.
- Checked "Connect it to the active virtual machine."
- Checked "Mirror Windows-connected drives on Mac." (Isolation violation.)
- Unchecked "Isolate Mac from virtual machine)". (Isolation violation.)
- Booted VM OS X.
- Finder Preferences: Checke everything except "Connected servers".
When inserted, it did not appear on the VM OS X desktop.
- It does not show up in VM OS X Disk Utility.
- Mounted a different USB thumb drive. It showed up on the VM OS X desktop and not on the host OS X desktop.
- Shutdown VM OS X, quit Parallels Desktop, and rebooted the host OS X.
- Plugged it into the other USB port.
Still does not shop up on the VM OS X desktop.

Any other ideas?

 

Host OS X and Parallels 11.0.1 (31277) were up to date.
VM OS X was not. I ran an "Update All" and that is not up to date.
I instead a new USB drive with "Connect it to the active virtual machine" checked.
It mounted on the VM OS X.
I changed the setting to ask. It asked when I mounted the new USB drive.
I shutdown the VM OS X, interred both USB drives, and copied the data from the first to the second USB drive.
(Both drives are formatted "Mac OS Extended (Journaled)".
So it is a mystery and will most likely remain so.
I can toss the first USB drive since I the second one has its data and works properly.
If you think of anything else to try, let me know (for curiosity and Parallels Desktop debugging purposes).
Otherwise I'll just move on, having worked this out with a kludge.