I have or had a similar problem: I set the phone to de-activate when in sleep mode. When activating the phone again, the Wifi didn't work. I had to restart the phone.
Nokia Support recommended to to set the phone to have Wifi always active when in sleep mode.
You find this setting here:
Settings > Network & Internet > Wifi > Wifi settings > Advanced > Wifi in sleep mode
Network & Internet / Wi-Fi / Wi-Fi Preferences / Advanced
Just got Oreo on Nokia 8 today. Vodafone UK
Not Perfect. Wireless is lagging and cuts off. Browsing is a nightmare on WiFi. Apps lag sending and refreshing data. Phone is absolutely fine in 4G. Anyone else?
Yep, clearly software. How are there so many issues coming up and they weren't caught on beta or in house testing?
Same problem here! Disconnecting all the time and it seems to get worse.
Sounds like I get a notification, so, unlock the phone to check and nothing there. Yep, thats the WiFi disconnected for 3 seconds and back on.
Getting the same issue. Browsing over WiFi very laggy and sometimes looses internet connection. Also getting the WiFi disconnected notification at regular intervals. Phone was fine before updating to Oreo.
Thanks for the info. Running wpa2-psk with AES in compatibility mode. Its set to detect and switch to channel with least congestion. Don't have option of disabling GI. If I reboot my phone i get a good internet connection for nearly half a day then it starts playing up again. No other devices have same issue. All I can think of is some sort of memory leakage in the WiFi driver / software. Didn't have the issue until Oreo update came down. Hoping someone has found a work around also logged a support call with Nokia.