I used a hotel's (most probably commercial) WLAN connection recently. One had to connect to an unencrypted WLAN and was then, when opening the first website, forwarded to a site where one had to type a username and a password to be able to really use it. This worked fine the first time, but after reconnecting later, Falkon told the site (google.com) was not available. Pinging google.com actually gave me "Target net probhibited". After testing a bit (I thought this was probably some Linux related problem with the WLAN stuff), I found out that Falkon did not forward me to that login page. I opened Firefox, which told me something like "Probably, you have to login to be ablte to use this connection", and then forwarded me to that login page on the first HTTP request. After that (I didn't even had to re-login), I could use Falkon again: When opening some URL, I saw that login page for a short time, telling me that I was successfully logged in, and then I could surf normally. I'm not used to such connections (I'm not in hotels very often), but I think as of now, Falkon can't detect such a connection and simply tells me the connection isn't working instead of what(ever) e. g. Firefox (and possibly otehr browsers as well) does/knows/detects. So I think it would be nice to cover this case of "Target net prohibited until another login happens".
Just to update this one: I just re-used the WLAN connection I wrote about last year, and it's still the same issue with Falkon 3.1.0: After re-connecting the network, I can't access the internet with Falkon. Using Firefox, it shows a popup banderole on the top "You have to login to this network" (or such). After clicking there, I can use the connection, also with Falkon. So still, Firefox knows about those "login needed" networks, and Falkon doesn't (and one still could think something is wrong with the connection).
So, it's one year and I'm still facing the same problem ;-) Aüpparently, Falkon doesn't follow the redirect ("Location" header) announced by the router before the login. This is what "LC_ALL=C wget --server-response google.de" outputs: tobias@think ~ $ LC_ALL=C wget --server-response google.de --2020-08-16 19:26:30-- http://google.de/ Resolving google.de... 172.217.23.35, 2a00:1450:4016:804::2003 Connecting to google.de|172.217.23.35|:80... connected. HTTP request sent, awaiting response... HTTP/1.1 302 Hotspot login required Cache-Control: no-cache Content-Length: 135 Content-Type: text/html Date: Sun, 16 Aug 2020 10:53:15 GMT Expires: 0 Location: http://172.18.0.133/login?dst=http%3A%2F%2Fgoogle.de%2F Location: http://172.18.0.133/login?dst=http%3A%2F%2Fgoogle.de%2F [following] --2020-08-16 19:26:30-- http://172.18.0.133/login?dst=http%3A%2F%2Fgoogle.de%2F Connecting to 172.18.0.133:80... connected. HTTP request sent, awaiting response... HTTP/1.1 200 OK Cache-Control: no-cache Connection: Keep-Alive Content-Length: 4540 Content-Type: text/html Date: Sun, 16 Aug 2020 10:53:15 GMT Expires: 0 Length: 4540 (4.4K) [text/html] Saving to: 'index.html' It answers with "HTTP/1.1 302 Hotspot login required", followed by the hotspot's login page "Location: http://172.18.0.133/login". Shouldn't Falkon follow this redirect? Like wget, Firefox and Chrome do?