Doorbell2 Intercom Chime

I added the Diode to the Doorbell2.Doorbell2 works fine without any issues.I connected the Doorbell2 to my existing M&S Intercom wires.Now, my Intercom is constantly chiming as though someone is pressing the button constantly. When I press the button, the doorbell2 works fine with no issues, however, I have this constant chime in my house from the M&S Intercom.What am I doing wrong?