How do I make AnyConnect connect at first try in a public WLAN that needs a confirmation click in a pop up window? It always needs a second try

With AnyConnect, if I am in an unknown WLAN that needs a confirmation of the rules in a pop up window at first login, I need to double connect to the network to fully load the login site, be it in a restaurant or train or wherever. The first try loads the pop up for the login but stops before it has been loaded showing your connection is broken together with a broken button to refresh, and a click on that broken button does not work, it is just not loaded well enough. If I log in to a known password protected WLAN that does not need this confirmation, I can enter the internet at once. How can

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