CDU and xplane 11

Cdu shows its connected, I click on 737 ng and get nothing. I have had this for over a year and its always worked. It works with xplane 12 but not 11 Thanks

Are you saying that you have been using the CDU in XP11 for the past year and only recently had issues?

Make sure you have the CS plug-in installed fpr XP11, it sounds like it’s only installed in XP12.