Enter your password manually. If you paste your password into the input field, double check that the system didn't add a space at the end of your password.
If you've confirmed that your password is entered correctly, place the feeder "close" to your router. Usually if the feeder is in the same room as the router, that's close enough. If there are multiple rooms or things that interfere with WiFi signal (e.g. appliances, steel, metal, concrete) between the feeder and router, the communication may be disrupted. When this occurs, messages have to be re-sent and the process may "timeout".
Putting the feeder and router in the same room can help the setup process succeed. After the setup succeeds, you may be able to place the feeder farther from the router within the limitations of WiFi signal.