T48G + Sennheiser Officerunner help

I know Yealink's supported wireless headset list doesn't list the Officerunner, but I was told elsewhere it works. I bought it and am trying to get it to work. I wired the phone up how Yealink shows in the EHS36 manual, when my phone rings I hear the headset beep, but it's not answering when I press the button. I was guessing I need a handset lifter, even though the manual doesn't show as needing one for a Sennheiser headset, just the Sennheiser Y-Cord. I tried lifting the handset to make a call and press the button and it's still not switching to the device. I tried setting the DIP switches with 1 up and 2 up. Nothing.

I'm assuming the Officerunner setup and how it works should be the same as the DW Pro & other Sennheiser wireless headsets. My question is for anyone who has any Sennheiser wireless headset. How did you get it to work? And did you need the handset lifter to answer calls? I'm thinking I do need that, but I want to get the headset working manually before I shell out more $$$. On the Officerunner base I just have a cable plugged into the phone jack, should I have something plugged into headset? I Googled and couldn't find anything on how to connect stuff, so I just followed the diagram in the ESH36 user guide which seems very basic.

My phone + the headset have both been upgraded to their latest firmware