Hi Elisa,
I can confirm your problem to some extend. My router at home (some Fritzbox) allows “WPA2”, “WPA/WPA2” and “WPA” for encryption. And there “WPA2” does not work.
At work, connecting to a “WPA2” WiFi is no problem though.
(See also How do I know the type of wifi security actually being used?)
Unfortunately I have no solution for this.