I'm flashing the Ubiquiti Bullet AC 3.24.10 and following the instructions it does come up but:
1) Switches from 192.168.1.20 to 192.168.1.1 and does DHCP service.
2) Only Telnet and ssh services running, no webservice.
3) The ash CLI is running and you can telnet or ssh in.
So sysupgrade to the nightly build, now web service works with the new UI but lots of stuff missing. I can change the node name, password, and location, but the usual "todo" list isn't there, just a blank yellow area. Most normal new UI stuff is missing.