The new Panasonic Hookswitch does have a different type of set up from other Sennheiser Hookswitches. (See Quick Start Guide below.)
The main thing you’ll want to be sure to check is that you have the V133 firmware on your Sennheiser Wireless headsets. The Panasonic mode is only supported on this Firmware version. If needed, please reach out to Product Support (800) 923-0018. But if you're curious, check out this link where EPOS Connect can be downloaded.