Today I encountered a weird problem with my network connection. I am not 100% sure the cause is GrapheneOS, but I am documenting this in case more people have the problem.
I woke up and my phone was continuously connecting to my WiFi AP and getting disconnected. So, I restarted it and it seemed to work again. However, after that another device could not get a DHCP lease anymore. I looked at the DHCP leases and they had all been given out at half past 2 in the night, when nobody was awake. What's more, they were requested by devices with seemingly random MAC addresses because their OUI did not correspond to any registered ones. At this point I could think of two causes: a problem with MAC address randomization of some device, or a prankster. I think the former is more plausible.
To my knowing, the only devices on my network that do MAC address randomization are some iOS devices and my Pixel 4a with GrapheneOS. I don't think it's likely iOS is at fault, or I would see this online more often but correct me if I'm wrong. So I concluded GrapheneOS might be at fault. Then I realized: maybe the behaviour in the morning of continuously reconnecting caused the DHCP starvation in the first place. Perhaps each time GrapheneOS would connect with the AP, it would do this with a random MAC address, request an IP and then disappear again.
For now, I released some DHCP leases manually and everything works again. Any comments are appreciated.