FFmpeg rtmp listen not working correctly: Connection Refused
Try to use static build of ffmpeg without librtmp. You can download it from the website, or build by yourself. I've got the same problem, but without this lib I could run ffmpeg listener. Also when I tried to stream to external rtmp host, I've got issue when streaming unexpectedly stop. As described in the end of this ticket https://trac.ffmpeg.org/ticket/7547