Wifi coneected no internet.

[Lejuames1]

 My laptop connects fine via Wi-Fi, but my phone (Sony Z3 Compact ) is not able to stably connect to the internet. The Sony runs on Android 6.0.1   I have tried Safe mode and software update. 

What happens, in the space of about 5 seconds, is:

1) phone searches for wi-fi networks
2) finds and connects to my home wi-fi network
3) says "connected, no internet"
4) disconnects and disappears from list of available networks
5) return to step 1...

Sometimes, I might get 2 seconds of internet between step 2 and 3 (proof that internet does work!), but it almost immediately disconnects.

What I have tried so far, but none of which have worked: 

1) Soft reboot of router and phone. 
2) Factory reset of both router and phones
3) Static IP settings for both phones 
4) Safe mode in both phones
5) Wifi Fixer
6) Desyncing and resyncing router and phone location times

Anything that I may have missed here? Or is this possibly a hardware fault? The "connected, no internet" thing only started happening a few days ago, before which this never happened. Would greatly appreciate your help in diagnosing this!

[ghencea-RO]

I've noticed that activating stamina mode blocks for some reason the wifi connections (using VPN or mobile to PC file transfers apps).

[ChoyChoyChoy]

I am experiencing the exact problem that he has. It has been going on for a few days now, I have done factory resetting. I have repaired the software through the Sony PC Companion but still the problem persists. Hope we have someone who can answer this question, I have been researching for the past few days but haven't found anything that can resolve the issue.

Edit:

Visit this post; titled No Wifi Connection + Bluetooth signal lost after 30 seconds . There's a little discussion there saying that this is an ongoing issue and that even other models are having the same problem.

[Lejuames1]

I have tried all suggested resolutions with no change. I have even bought a new router to rule out router issues but this problem is determined to be an issue with Sony Z3 compact. I have contacted Sony but they are looking for an astronomical fee for a technician to look at. Im really disappointed in the level of customer service from Sony. My phone has been returned several time for repair within warranty for various issues. I have too many issues with this phone since i bought it and now that it is out of warranty an extortionant mount of money is required to have them look at it.   I have been using Sony phones and products for a lifetime. I may need to consider my relationship with Sony unfortunately.  Disappointed.