Guys, I had the same problem, and I know it’s a long time since you’ve posted here. but my fix to the problem was actually funny, I tried everything and since the python addon needs some specific port and using personal host address, I thought maybe it’s because of firewall, So i Tried everything, long story short, I had to disable my VPN in order to everything start working at least it was my fix, Hope that it work for some of you.