iPhone started disconnecting from every wifi when is locked

As to the iPhone dropping the WiFi network when it is not connected to power that is part of the WiFi standard.

But it should rejoin any previously trusted network upon waking it up. Click on the Get Support link on the top right of this page and see about getting your iPhone tested.

I have the same issue with iPhone 12 Pro and iOS 14.6. Sometimes it disconnects right after unlocking the phone (I am able to see the wifi icon go away and 4g icon come). Most of the time it takes about a minute for it to reconnect despite that in the wifi settings page it shows that it is connected. See the embedded video.

This issue started to happen a few weeks ago (maybe after updating to iOS 14.6) with all wifi networks.

I don't believe that this behavior is by standard as I am using mobile data for about a minute after unlocking my phone, and if mobile data is turned off, I have no internet access.

I have tried everything the author of this topic mentioned too and it does not help. I hope that someone from Apple can look into this issue.

https://www.youtube.com/watch?v=Yl8yejkESO0

That's not correct. I have the same issue with my iPhone 11 with iOS 14.6, but my wife's iPhone (exactly same model and iOS update) is not experiencing that issue. Wifi is supposed to be connected at all times if available, otherwise the background app updates would be using cellular data.

I also tried everything to fix, no luck. Next step will be to reinstalling the iOS 14.6 with the phone connected to my macbook. Let's see.

Hi, only thing what helps me is when play music on background turn down volume and let it play. Hope it helps, have a nice day

Me too

Ios 14.7 same wifi disconnect wifi when lock screen