I am in a bad place with my home network. I made a WiFi, where Linux and MacOS work, but Android does not. Says there's no connectivity.

Of course, connectivity is just fine, and applications work when they do not care about that. For example, WatsUp simply connects where it wants. But Chrome is too polite for that and refuses to try.

A tcpdump shows that Android connects, attempts SSDP (which never worked in my networks), then pokers the router (sic) with HTTP, and then reports the there's no connectivity. All Android devices behave the same way.

Banging my head figuratively.