Unresponsive Keyboard After Waking Mac
Apple seems to do all kinds of weird networking stuff. For instance, during wakeup, your T2 equipped Macbook will wait for a DNS response and then use said DNS response to synchronize time via NTP before letting the user use the keyboard. Probably checking timestamps on signatures for the keyboard firmware, or something stupid like that. This only happens if it happens to have a default route.
Similarly, all macOS machines will test a DHCP supplied default route before applying it by trying to reach something on the internet. So if you happen to have some firewall rules that block internet access, no default route will be applied until the internet check times out.
Previously:
Update (2020-11-02): Ben Kuhn:
I noticed my MacBook would sometimes become unresponsive to keyboard input after opening the lid.
Eventually I realized it only happened in my backyard. WTF?!
Finally figured out why and the answer is... horrifying
