In places where the signal is weak, it constantly tries to switch between the Wifi and the phone network, and there is no signal / connection at all at that time.
I also noticed that I do not get a “login page” on public Wifi networks (where you usually have to press “I accept”). There is just a “page not found” error message, and the page might only appear for a very short time. At one time, it worked anyway, but only for one minute.
However, on two Wifi networks I am “regulary” connected to, everything works fine (unless in spots where the signal is weak).