@Lambretta74 wrote:
What might does it mean? Does it random, then works properly, than does it again...
Device: sony xperia xz premium few months old.
https://ibb.co/vjBfW34
https://ibb.co/m97vvNC
https://ibb.co/yP5PQhX
That is really a bad condition... Did anything heavy fell on the screen or any pressure application? Is phone subjected to any liquid or did any water photography recently?
If it continues the basic thing to do is full factory reset , also need to turn off the phone for some time to see it solves by itself. If still persists , needs to be inspected by Sony service centre.. it looks like display issue but if the board has any problem also those pattern can be formed on screen..
Contact local Sony service after a factor reset or Xperia companion repair...to ensure nothing from software side has any effect on it ..
