Facing network issue after updating oneui 5.1 on A71

[kaosar]

Facing network issue after updating oneui 5.1 on A71. Poor network connection on network bar. Wifi also slow. How to fix it? Trying to revert. If possible to solve please let me know. I cant make call anyone. 

[BandOfBrothers]

Once an update has been downloaded and applied you cannot revert back to the previous software via your phone's settings @kaosar 

Try the following please 

• Settings > General Management > Reset > Reset Network Connection > Soft reboot by turning the phone Off and On. 
• Clear Cache Files from the phone's System Partition Section  > https://www.samsung.com/uk/support/mobile-devices/how-do-i-clear-the-cache-on-my-device/ You may need to insert your earphones or hook upto a powered On Laptop to access the Clear Partition Section. This may help with lag or stutters as this clears the phone of old/unused or broken cache files.There is also a Repair Apps option in the Menu System too. 

[Shahab11]

I am facing network issue. My both of the sim's network is often distorted. It mostly shows emergency.