I keep having a number, 1009, calling me. When I try to answer it, my RC Call Controller freezes up and I cannot answer or hang up or send to voicemail. I have to restart it every time this happens. I can make and take regular calls without any problem. Not to happy about this at all.
We had a similar issue. They advised in the settings turning the "Set port automatically" to off, and then choosing a port - in this case 5084. There are other port numbers that may work. This is a screen shot from the Ringcentral for Mac.