Thanks for being a part of Samsung community. We apologize for the issue you are facing in the device after update. We would like to suggest you kindly follow the below mention steps to overcome the Issue;
- Check by using any other SIM card. - Ensure that network frequency of your device should be selected on Auto-mode. - Menu > Settings > Connections > More Networks > Mobile Networks > Network Mode > Select auto mode (GSM/WCDMA/LTE). - Search for the Network Manually as follows: Menu > Settings > Connections > More Networks > Mobile Networks > Network Operators > Select Manual Search. - Kindly go to settings >> General management >> Reset >> Reset network settings.
Be sure to hit ♡ when you find an answer that works for you. For Further assistance, you can get in touch with us via Live Chat option by following- http://livechat.support.samsung.com/Customer_new/IN. You can also connect us via Samsung Members web community by following mentioned url-https://community.samsungmembers.com/en_IN#/
