After the latest update, the grandstream phones on the network works as per normal but with the Fanvil phones, we cannot dial locally and also cannot make outbound calls. It worked for more than a year and now it is messing around. I have a Yeastar S100. On my router, my settings have always been disabled sip, DST-nat 5060-5061 to PBX and also RTP ports. Why would it just stop working?