Western Digital External USB HDD is not block through SEP as server base policy applied through SEPM

i have seen the i block all the external usb drive flash etc

and USB flash are blocked but when i pluggin a western digital USB external hdd sep does not block this

(i made a server base policy for block usb mass storage/flash etc drive )

is there any of the patch or task missing to perform kindly guide me

Thanks

Haroon

92-333-3670519