No internet connection on S7 and S7 Edge on specific wifi

[AC Question]

I have an S7 Edge and my dad have an S7, we both don't have internet connection on one specific wifi, other devices like iPads, iPhones work fine on it, even a galaxy S4 with Android 6.0.1 ( CM ).

I've tried everything and my software is up to date but nothing seems to work.

How can I fix this ?