I dropped my phone in the bathtub. When it came out, I felt nothing wrong. then I dried it with a towel, It could still work normally.
Turned it off when I was sleeping last night.Today I turned on my mobile phone and found it could not be turned on.
My guess is that the phone has been water damaged. You can disassemble the phone and check the water indicator to see if it is red,
Drop in bathtub has results iPhone 7 Plus motherboard damaged. You can check our iPhone7 Plus won’t turn on after water damaged (https://www.youtube.com/watch?v=OJFngzyqp2E&t=101s), maybe you will get something from it.