detach-mirror with mirror point to an extent

I used detach-mirror on a device, but the --mirror argument incorrectly pointed to an extent object. The result returned an error, but this extent leg was actually removed. I also got a new isolated virtual volume and extent.
This virtual volume is unexported and cannot be deleted (the message shows that it does not exists), but it actually exists in the INTERFACE and CLI.
The extent status is also in used, but no parent , and cannot be deleted also.
How to solve this problem?