To test my own apps on an IPv6 network, I usually share a WiFi network using the option-click method in Sharing menu. This enables me to create a nat64 network. However, since my upgrade to iOS14 and Mac OS Catalina, this network is no longer giving me access to the internet. With an iOS13 device it does work. The behavior I see is that I get 2 IPv6 addresses, and a link-local IPv4 address. After connecting, iOS at some points prompts that this network has no connectivity and asks me if I want to stay connected. I found a related thread on the chinese forum that seems to describe the exact same situation: https://discussionschinese.apple.com/thread/251973678 I wonder whether there are more developers who have run into this issue.