WiFi authentication problem I have got my android (Lenovo Vibe P1M) and for a couple of days my WiFi worked smoothly.But when i tried connecting it yesterday it says authentication problem. 

While my family members can use the WiFi with their phones, I can't.

What I've tried so far: 

1. turning my WiFi on in Airplane mode.
2. clearing data from google services framework.
3. going far away from my router and trying to connect. 
4. factory resetting the phone once
5. Forgetting access points and resetting passwords.
6. restarting my hotspot several times
7. restarting my phone several times


nothing worked.

NOTE: I see this question has been asked before here but that doesn't solve my problem.

Does it mean there is a problem with my device?
In my case it was a full memory - deleted Gigabytes of photos -> worked