The 25i is compatible with both 2.5ghz and 5ghz wifi bands. The 25i should connect easily, however if they encounter issues, follow these steps. 

1. Make sure wifi password is correct, if you still experience the issue, proceed. 
2. Press and Hold the AUTO button until it blinks.
3. Once Wi-Fi icon is blinking, remove front panel for 2-5 seconds.
4. Replace panel.
5. Fully re-attempt the app pairing process.