Once I need to add an IP adress to a SIP Trunk, since I'm not able to modify it, I have to delete the existing SIP Trunk and to create a new one. The thing is when I do delete the old one and create the new one, apparently everything happens as it should (I'm even shown success msgs), but once I refresh the page, nothing change: I'm stuck once again with the old one as it has never been deleted, and I'm once again missing the new one as I've never created it.