Hi everyone, i upgraded the software to Android 8.0.0 last week ( Samsung S7). everything went smoothly since then. But as of yesterday out of the blue my phone lost connectivity and kept giving ''Network not registered" and some error MM... i factory reset the phone twice after reading online that its the ultimate fix. But that didnt work. Apparently many people have had the same issue after the update. has anyone here been in my shoes? if so how did you fix it? appreciate your help.

I called customer service and the dude has no idea what i was talking about so i just said ok thanks for your help.

Edit: i know why this has happened from reading online. i just want a fix because i tried and didnt work for me.