Issue connecting Jabra BIZ 2300II to CISCO CP8811 desk phone with GN1216 cord

Hi folks, hope this is the right place of ask this.

Our office recently updated all desk phones to CISCO CP8811. I have a Jabra BIZ 2300 II headset that I’m trying to connect to the phone. Our manager got a Jabra GN1216 Avaya one-x adapter cord for it.

The connectors all seem to fit correctly, however I cannot hear a dial tone through the headset no matter which position I put it on. The set up sheet suggests it should be in position 3 which matches the item number on the headset. But I have checked the phone settings many times and still cannot hear a dial tone. When I pick up the receiver, the dial tone is present though.

Is this an issue with the adapter cord? Should we be getting a different one?

Any insight will be appreciated, as I’m not sure where to look. Thanks!