Yeah. Read something about this here:
root@raspi:~# netstat -tulpen | grep 10000
udp 0 0 192.168.188.28:10000 0.0.0.0:* 0 108942 13985/lxd
That at least fixed it. Yet, I would not expect this behavior.
Unfortunately, that does not fix the audio/video issue 
Also nmap doesn’t show 10000. :-/