*Problem solved, but the root cause is still unknown
Had this strange issue with my XZ2C and my router recently, where every time I checked my phone after a period of not using it, everyone connected to the same network would get disconnected/reconnected. Not a big issue if you're just browsing, but definitely annoying if you're in the middle of an online game.
I tried all the standard troubleshooting steps(reboot phone/router, boot in safe mode, etc.), but nothing seemed to help, and I had trouble reproducing the problem reliably. Eventually, I tried forgetting the network and reconnecting to it, which was a fairly reliable way of triggering the disconnect.
After figuring this out, I eventually managed to pinpoint one setting which seemed to be causing this: I had previously set "Keep WiFi on during sleep" to Never. Switching this to "Always" resolved the issue, and I was unable to reproduce it afterwards. For testing purposes, I switched it back to "Only when plugged in", but this resulted in another disconnect after forgetting the wifi network.
I'm not sure if this is simply an incompatibility issue between the XZ2C and my router, or whether there are others facing the same problem. Obviously, keeping the wifi on during sleep will consume more battery, but it sure beats having to reconnect every time I check my phone. Hopefully SONY can find a way to fix the problem so I can go back to the default setting.
Details:
Phone: Xperia XZ2 Compact (H8324)
Android version: 8.0.0
Build number: 51.1.A.4.225
Router: ASUS RT-N66U
Router firmware: Merlin@520760e v380.70
Devices connected: (all wireless) 2 Laptops, 2 iPads, 3 smartphones, 1 Smart TV, 1 Printer
