Fixed an annoying one on my UniFi gateways: after a PPPoE reconnect or a reboot, the ISP hands out a new IPv6 prefix. On a single-WAN gateway UniFi never tells the LAN that the old one is dead, so iPhones and Macs keep using it for up to 24 hours. Wi-Fi says connected, nothing loads.
A small Python daemon now sends the missing "deprecated" router advertisement. Running on a UCG Max (o2) and a UCG Ultra (1&1). PR for the community add-ons:
https://github.com/unifi-utilities/unifi-common-addons/pull/39