Can Somebody please tell me how to fix this issue in my s21 Fe , A white line appears out of no where, please help

Dont buy s21FE 

My s21FE is overheated every time and bettry drained really very fast . worst FE model

i am using Samsung s21 FE from past 1 Month. i have faced lot of heating issues while playing normal casual games and capturing photos for some time. the phone heats tooo much. i have used samsung a51 a71 also but not getting such issues. @samsung sh...