I have just set up my iPhone tunnel and when I click it starts right up and says connected. Then I open my 3CX iPhone 12 app and it says "On Hook" and I can do everything. The problem I am having is that when the tunnel app moves into the background it disconnects after a few minutes. How can I keep the tunnel connected? I don't see it listed in the "Background App Refresh" section as an app I can tell it to remain open in the background. How am I supposed to receive phone calls when the tunnel is always disconnected? I am very frustrated. Any help would be appreciated. Thanks.