USB smart card reader umounts randomly

[itsme300]

card reader works for some hours and umounts suddenly and won't attach to VM even on the action of detach and attach. I've to restart the VM to get it to work again.

Virtual box version : 6.1.12
host os : windows 10
guest os : Ubuntu 16.04

Code: Select all

$ pkcs15-tool -D
Using reader with a card: OMNIKEY AG CardMan 3121 Rev. B [OMNIKEY 3x21 Smart Card Reader] 01 00

Code: Select all

$ lsusb
Bus 002 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
Bus 001 Device 004: ID 076b:3031 OmniKey AG
Bus 001 Device 003: ID 80ee:0021 VirtualBox USB Tablet
Bus 001 Device 002: ID 04e6:5115 SCM Microsystems, Inc. SCR335 SmartCard Reader
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub