I am using both a MAC and windows 10 PCs to 'listen' to my KiwiSDR. On the Windows PCs I have been 'enjoying' frequent instances of 'Audio underruns', while on the MAC nor on my iPad Pro I experienced such problem. I tried changing QoS, setting up a kiwisdr VLAN, nothing helped. BUT:
If I use the IP address:8073 instead of kiwisdr.local, the problem goes away!!
I hope this message can help someone experiencing this issue.