My desktop has a bunch of garbage IP addresses for docker containers and libvirt, these seem to bury the actually useful 192.168.. address. When my phone switches to Wi-Fi it attempts NAT traversal but seemingly only on the first 12 IP's and stays connected through the relay (I waited for a long time). It seems that max_remote_nat_traversal_addresses is effectively useless, 12 failed paths take up all available path "slots" and are never cleaned up even though more IPs are there and could be used for more attempts (a really useful IP is stuck there).