I am adding a reply in here from our chat conversation.
1. Please update to 0.14.2, and run the test again. (Did so, same issue).
2. Update the Realtek NIC drivers, and run test again (Did so, same issue).
3. Fenrir noted that the issue described happens to him when using nginx and the RTMP module w/OBS. OBS_BUG is going to verify with the Azubu team if that is what they are using.
If Azubu IS using nginx with the RTMP module, then they might want to move away from that combo. The RTMP module is no longer supported or being developed and has issues.