I received the Oreo update yesterday and installed it. As it is done on wifi I did not notice any problem at first. But after a few hours I noticed I can't access Internet if I'm not connected on wifi despite the 4G logo displayed on the screen headline. I can make call and receive SMS. I've checked the status of the network and no problem is reported by the network provider. I've checked the phone settings and all seems to be properly adjusted.
Any idea to help me?
What usercub suggested is worth trying, also if you haven't already restarting your phone is worth a try. Failing that you may need to factory reset and set your phone up again. I've personally not had any issues with 3g or 4g data connection after receiving Oreo so I don't think their is a general issue with the firmware. For whatever reason I think it is more likely you've had some bad luck and perhaps something didn't go quite right when it updated. If you make sure all your photos etc are backed up to your Google account a factory reset isn't so painful as it sounds and will often resolve these types of problem. If it doesn't then you would need to take your device into a service centre so they can manually re-flash your firmware.