This manual setting of the IPv4 is the only foolproof way to do this and no clue why Apple is taking so long to fix an near essential issue - this should be a clear part of any qualification test for release software. Impact is very widespread it seems.
Set IPv4 to manual on your TCP/IP settings (click details on a mac for your WIFI connection)
Set IPv4 to 172.20.10.x, where X is anything from 2 to 254 (if you have more than one device you can use unique IPs)
Set Mask to 255.255.255.0
Set Router/Gateway to 172.20.10.1.
Change this EVERY time you move to a different WIFI.
Call support and complain