Switching Between Networks with Landing Pages - Caching Problem

I'm changing between various hotel networks and provider hotspots quite often. With most of these networks I have often serious problems. It takes ages until it finds the "captive" landing page that is used by most of them. Sometimes this only works when I directly try the address I stored last time. Even then, it takes a very long time to load the landing page. After successful login, the connection seems to be fine. I also saw differences between Safari and Chrome in finding the landing page. I never have these problems with direct connections that use a plain WPA2 authorization instead of a landing page. I start to hate those pages.

Sometimes turning WiFi off/on heels, sometimes it doesn't. On IP level, everything seems to be fine. So I assume some routing/cache problem. Could this be some cache issue that could be solved by some kind of flush command?