Hello All
Was there any progress with this forum, I am currently having the same issue. The headset works absolutely fine with great volume plugged directly into the laptop USB port. However, when plugged into a Cisco 9951 the volume of the headset drops making it very hard to hear the caller on the other line. When using the handset there are no issues with volume. I have checked the configuration of the hard phone and the volume is set to the max.
Kind regards