Are you going back to the UvA soon? Then reset your wifi on your mobile phone and laptop through wifiportal.uva.nl. You can already do this from home.
The current wifi certificate expires on April 27. This means you will no longer be able to connect to the wifi network on location (uva and eduroam). When you log in to the wifi portal you will receive a new certificate. Please sort it out right away so you will have safe and fast wifi when you get back to the UvA!
Read more on wifi in the A-Z.