Even though it wasn't a Meraki specific issue, here is the solution. (Just in case someone else is searching the internet for the same issue and bumps into this thread.) We needed to make an HTTP exception in our Watchguard Firewall. When a Nintendo Switch connects to a network it immediately tries to connect to ctest.cdn.nintendo.net and it wants to get a response in a specific way. It looks like our HTTP Proxy was stripping some of that information, so it was failing - and the Nintendo Switch was interpreting this as there being a splash page needing a confirmation from the user first before it could join the network. (Hence why it was asking for the user to register to use the network.) An HTTP-Proxy exemption allows devices to connect to ctest.cdn.nintendo.net and then it finalizes connecting to a network. https://www.reddit.com/r/networking/comments/10dau9j/anyone_know_how_to_register_a_nintendo_switch_to/   https://www.watchguard.com/help/docs/help-center/en-US/Content/en-US/Fireware/proxies/http/http_proxy_exceptions_c.html ... View more