It seems that the problematic version of the 4.3 update is not only limited to US carriers, recently, we have been receiving messages from Android Smartphone users worldwide about the same update bringing about various issues like the losing network, some apps failing to work and others. Affected devices are almost every Android products out there, but the most reports are coming in from Nexus 4 users.
Here is another message about a Galaxy Note 2 auto switching network just after updating to 4.3 from Vinay:
“I, very recently, updated my Samsung Note 2 to 4.3 over the air in India. Ever since, I have been having a problem. Everytime I switch off the phone (as at night for recharging the battery after a heavy usage with Internet, etc) it automatically switches its preferred network upon switching it back to On in the morning. I have to go to Settings>More Networks>Mobile Networks>Network Operators and convert it to Automatic Selection. After waiting a few seconds the network data symbol on top of the screen would come out. Everything else in the device is working fine. Thank you.”
Possible Solution to Galaxy Note 2 Auto Switching Network After Installation of 4.3 Update
A Factory Reset is recommended after updating your OS version especially if your device is showing some issues after the process. This will somehow help in removing glitches after the switch. Be sure to back up your data though prior to this.
If that does not work, you can report the issue to your carrier so they can coordinate with Samsung for a fix, especially if there seems to be a significant number of people negatively affected by the update.
Another alternative if you cannot wait for an update is to flash your device and install an earlier version of its firmware. This process is risky though so better do your research well before performing it or have someone who knows the whole process to help you.