Voicemail Notification on Button


I have some S400 and S500 phones with the Voicemail phone app assigned to a button on the screen. It is normally green but when there is a voicemail, it goes red. After clearing the voicemail, sometimes it reverts back to green, and sometimes it doesn’t. What is this setting and how do I fix or control this?

Sangoma thinks about the BLF light a bit differently than all other telephones in the world.
For Sangoma phones, the Green BLF key = LED OFF and Red = LED ON.
I wish the BLF key to be LED OFF for on Hook or idle, LED RED = RING and LED GREEN = OPTIONAL Feature.

I don’t think this has changed yet.