I’ve managed to make a particular extension invisible to the Endpoint Manager.
I was trying to configure an extension using the ExtensionMapping option, filled out all of the information and then clicked the Use Selected button. The system whirred and came back, but the extension I used does not appear on the list of mapped extensions, nor does it appear on the dropdown list of available extensions if I click Add Extension.
I have also had this happen in 2 occasions. Both times I was able to go I to advanced settings of the extension and set it up there. Voila it reappeared.
Help, yes. But it didn’t work. We are using FreePBX 12.0.76.4 and your screen shots look like come from a different version. We have plans to upgrade to 13.x, so will try again when we do that.