When I turn on true tone display on my XR, my eyes (caruncula?) will start pain in few minutes. Then I turn off true tone it will much better till back to usual. I usually use my phone turned off the true tone, and there’s nothing happened, I use Samsung s9+ before, it’s oled screen and even I scroll the brightness to the lowest , I didn’t feel any uncomfortable. I’m strange because it’s oled hurts eyes in common..