Iam also have same issue.After the update I get low coverage of network in both SIM Before it was not like that.Some times there occured a problem with the call also.
Dear Samsung Member,
Greetings from Samsung Customer Support!
Kindly follow the below mentioned step to improve the performance of the device:
If the issue still persists, kindly attach the log file and send it to us in the Samsung member application (attach when the issue occurs within first 15 minutes of the occurrence of the issue.):-
Samsung Members App > Feedback >Error report > Attach log file for any issue
Thank you for writing to Samsung.
Samsung Customer Support