WIFI keeps disconnecting when iPhone is locked/idle/asleep

My iPhone 11 is only 1 day old and I just recently updated to iOS 14.0.1, the wifi keeps disconnecting whenever my phone is locked/asleep. I have tried resetting the network, forget wifi and reconnect, but to no avail it still is disconnecting. This is frustrating because I need to get notified from my phone. Is this a software issue from iOS 14 or just my phone? Are there any more solutions?

Hope you can help me.

Thanks!