Why does wifi give authentication error?

[Android Central Question]

I keep getting an authentication error for my wifi networks - home, work, other known networks. If I turn wifi off and back on, it will reconnect but then it will give me error again after a while. Any ideas? Samsung Galaxy S6, Android Version 7.0. Started happening about 3 or 4 weeks ago.

 

[B. Diddy]

Welcome to Android Central! Does this also happen in Safe Mode? https://support.t-mobile.com/docs/DOC-29226