For public wifi networks (trains, airport, etc) that needs authentication, sometimes just clicking connect button is enough, firefox generally detects and shows a warning (for example on the Librem 5). But that is not working on flx1. I have to run ip r and then visit the gateway ip manually to get the authentication page.
the only thing i can think of is the connectivity check URL of network manager. i don't know what purism uses but there might be a misconfiguration on our side if some portals do not work