I have at least one issue which may be causing another, but I'll mainly deal with one that has more clear evidence.
I noticed that my zigbee lights (Philips hue bulbs) only come on 50% of the time given an app that turns them on at a certain time in the evening and turns them off in the morning. I thought maybe the HE needed a restart, so went to Settings and restarted. After it came up, it took 10 seconds for any link to resolve in the HE web interface. I had a hunch this was due to HE trying to reach the WAN but not being able to because I blocked it at the firewall level. I disabled the firewall rule for one second, and everything in the web interface was fast again. Is there a way to fix it so that HE does not need a WAN connection and to make external connections in order to function?