Wifi keeps disconnecting

[Android Central Question]

Since some days my phone is having wifi problems. When I turn it on the wifi works normally for a while, but then it disconnects. If I try to reconnect, it says authentication error. The only way I have to make it work is restarting the phone or activating plane mode and then activating wifi again.
Any solution?

 

[methodman89]

Try in safe mode to see if it stays on. 3rd party apps you install can turn off your wifi.
I recently discovered a battery widget with a buried setting for shutting down the wifi. There are quite a few more.

 

[Dingydroid]

I have the same issue.
It happens on different wifi networks and not always. Sometimes reboot of the phone works and sometimes turning Flight mode on/off. And sometimes turning of the bluetooth works.
But today I had to reboot the phone and after that I had to even select 'Forget' for the WIFI network that it was constantly disconnecting from and enter the credentials(WPA key) again.
See screenshot with the error Android 7 gives.
I get the feeling that it has to do with the fact that Android can not read/decrypt/pass-on the saved WIFI credentials(WPA key or user name password)