Xperia Touch looses internet but remains connected to wi-fi

[ronb62]

Xperia Touch.

 Keeps dropping internet connectivity. Remains connected to wi-fi but no internet.

If I “forget” wi-fi connection and re-enter wifi password, it will reconnect but again only for a few minutes.

The dropping seems exacerbated by using anything involving DNS (but that could be my misinterpretation. Using just Youtube app seems to last longer -No idea why.

All other devices in house remain happy and connected wired and wireless. Tried connecting to other wi-fi hubs, both in my house and next doors (next doors is even a different ISP). Same situation.

The ‘Touch is 1m from the hub so connectivity to hub is not an issue. It will connect through the walls to next door!

When it looses internet connectivity the WI-fi symbol eventually displays the ! on top of the Radar symbol. Top rhs of screen and the info within wi-fi of system shows connected but no internet (I have put the device into developer mode).

I have tried re-installing software with Companion, restarts. Suggestions PLEASE !!

G1109. Android v 8.0.0 sec patch level 1 June 2018  :build 44.3.A.87

[Jess.09]

Try to perform a factory data reset for the device, sometimes it helps, from Settings > System > Reset > Tap Factory data reset  > Reset device.

[ronb62]

Have already tried factory reset and a full reinstall using the companion with no change. Also tried 4 different routers on different ISP. does the same  on all. 

[CosmicTomato]

You can try to change the Wi-Fi network security of your router.