So I've been having this issue for the last month+ and I have yet to find an answer. I have a Samsung Galaxy S6 running Android 7.0
My home wifi was working fine until one day, seemingly out of the blue, I started noticing my phone was not connected to wifi. When I would inspect the connection I see "authentication error occurred". I can put in the correct credentials and I still get the error. HOWEVER if I turn the wifi on my phone on and off it can auto connect to the router and will maintain a connection. So it appears the authentication error is not due to incorrect credentials. Sometimes I reboot the phone and that allows it to connect as well.
The phone has no problem with any other wireless access points and no other devices in the home have an issue with the router. I have other Android devices that don't have this problem.
I'm not even really sure what could cause this issue. Malware? Why would it only be between this specific phone and that specific router? Could anyone with some knowledge of networking be able to suggest what the problem could be?
adb logcatshould show you any errors or warnings in realtime.