Screen bright spot

Hi all, I upgraded to a galaxy s6 edge last week and I noticed that it was getting way too hot while charging, using the official charger. On searching android forums, many users were having the same issue and I thought that it was due to quick charge 2.0. Just 4 days after my upgrade, i noticed a bright spot on the screen (visible on a white screen). I took it to at&t store and got it replaced. The new phone doesn't get hot while charging at all and the at&t store rep said that she has been getting lots of galaxy s6 edge device replacements because of bright spots. Does this have something to do with quick charge or some units were faulty? Anyone has the same experience? And a bit of warning to run some device screen tests while you are within your 14 days replacement period.