Re- Wifi "hijacking" had something similar recently trying to get a bus ticket. Turns out the app was trying to access the bus companies wifi and of course it was behind one of those useless login screens- which the app did not present to you and was only evident if you opened up the browser.
And of course, the error message displayed had absolutely nothing to do with the app failing to get an internet connection.
Biting the hand that feeds IT
