I am not able to use 5g network. suddenly It's showing emergency network and only 4g network available. What should I do?

SINCE, I RESET MY PHONE,, IT'S GIVING ME AWESOME PERFORMANCE TILL YET. BATTERY  DEPARTMENT IS IMPROVED.PERFORMANCE LEVEL IS TOP NOTCH. HEATING ISSUE IS DECREASED. 120 Hzh WORK PROPERLY. CAMERA DEPARTMENT IS FABULOUS AFTER RESET.I SUGGEST TO YOU ALL ...

Worst phone ever.... Even 5g network not working.I have done all things to start 5g in my device, but it's failed.What could i do....? 

After APRIL SECURITY PATCH UPDATE , i noticed that my s21fe 888 is no more heating issue, camera department is IMPROVED.BATTERY BACKUP is awesome RIGHT NOW.GO AND UPDATE YOUR PHONE...珞

Since yesterday, i am facing network issue in my samsung s21fe sd888. It's not being switch in 5g....even my jio network suddenly disappeared. Very disappointed with samsung.