iPhone 13 screen turned black hours after water exposure even though it still works

My phone unfortunately got submerged in water today. I checked on what to do on Apple Support and the phone appeared to dry internally in four or five hours and I was able to charge it. The screen was normal and I was able to make calls and do everything normally. Four or five hours after that, the screen has gone black. You can still call it, text it, etc., but I can't answer it, call out, etc. because the screen is completely blank/black. Any ideas?

[Re-Titled by Moderator]

Original Title: Phone has black screen after getting wet