I recently upgraded my J5 to an A71, and after only a few mins of using I found it pulling terribly on my eyes, and after using I would feel kind of sea sick. I never had this issue with the J5.
After looking into what could be causing this the only thing I've come across that sounds possible is this DC Dimming, or PWM, but looking at the specs from the J5 this has it too -
Samsung Galaxy J5 2016 1280x720 AMOLED (Response Times PWM Frequency) 243.9
Samsung Galaxy A71 2400x1080 AMOLED (Response Times PWM Frequency) 247.5
I tried everything that was recommended (turn brightness down, blue filter, dark mode, 3rd party dimmer etc).
I've had to return the phone which is annoying as it was great apart from this, but I couldn't use it! I'm now stuck with an old J5 and concerned that whatever upgrade I get it will do the same!