Wifi drops when phone is locked after 10.3.3 update

Can anyone help me? My iPhone Incoming call shows only name and no number. Sometimes I need to know from which number s/he is calling. Currently I am using iPhone X

Is this only on WiFi?

No always

Have you tried turning of Auto-Login ?

No. But with turning off I would have to manually reconnect whenever it happens or when returning home...

where is that setting?

Settings->WiFi-> Tap the “ i “ symbol next to your connected network and you will see the options !

that really did the job. Thanks. Using iOS 11.2.1

I have auto-join only, ***? :O

1) WPA2- Personal, AES;

2) No, I don't have.

On iOS 11.2.1 I have auto-join only, there is no "auto-login". Should I hard reset my smartphone as new or what?

Auto Join means that your device connects again when disconnected.

If you say you’re device is losing the connection, keep it on so it reconnects. And I guess u don’t got low power mode

It doesn't matter, iPhone drops wi-fi while locked, even I keep "auto-join" on.

When I use iPhone, there are no problems with connection.

For your information I have a Router Home based and I get this feature. My router is Dlink

I have tried it with Digisol too and I get the same feature.

What Router are you using ?

Correct and this is the way it should behave !

But the issue happens when Auto-Login is turned on and the PING RESPONSE is too long or doesn't come at all.

Sorry that is Auto-Login and it is mentioned in Apple's Samples and Guides