iPhone says wrong WiFi password

I was at a relative's house, and tried to connect to their WiFi, but my iPhone kept saying the password was wrong. However we were able to connect with no problem from my MacBook, my sister's android phone and my brother's iPhone. His phone is also a 6 running 8.3. I had read where some people had a similar problem and found that it might take 10 attempts before the phone accepts it, but no such luck. And I carefully typed it in, so I know it was done right.