Whew! My #wip uses a Raspberry Pi #picoW, but for the life of me I couldn't get it to serve http to a browser. I tried connecting it to an old router and it worked there, but don't want to keep using it. I finally decided I'd try the router's primary network (not the guest network) and it worked as expected. Ha! That'll show me... trying to give restricted network access to a device I don't want to be exploited!
At least there's no way to access it if you don't have access to the LAN (which in my case is important).