Hi there,
Have you tried any third-party tool for your requirements?
On the Disk Management window, look for the DVD drive and set it to offline as a result, the disk becomes offline and loses its drive letter assignment. Now check if you can see the DVD that you need to add.
Attach USB device to Hyper-V guest machine https://learn.microsoft.com/en-us/answers/questions/707320/attach-usb-device-to-hyper-v-guest-machine.html
------------------------------------------------------------------------------------------------------------------------------------------------------------------------
--If the reply is helpful, please Upvote and Accept it as an answer–