It's a hardware issue. Samsung does not acknowledge that they have faulty amoled screens. If you're past your warranty, you need to shell out 11k+ just to have it replaced. This issue persist from Samsung s9 up to note 10 (within that generation).
That's why I'm switching since Samsung doesn't care about their customers. I've been to their service center in sm north edsa and based on the numerous people inside on a sunday afternoon, just means their devices are really not good.
