delay in response?

hey guys, i am using my S6 for more than 5 months, overall everything is good, but since the beginning i am noticing one issue, on the home screen, when i press on a folder sometimes it opens in delay of about 1.5-2 seconds, the sound of the press itself has the same delay too, you press and nothing happens, after 2 seconds you hear the pressing sound and it opens, it's not only with folders, also with any app on the home screen, it doesn't happen all the time, but when it happens you just don't know if you clicked on the app/folder or not, you have to wait....since i bought my phone i have done 2 factory resets and updated to 5.1.1 through OTA....and this issue still persist....can anyone help? i was thinking of returning the phone or fix it, but it's hard to show what the issue is because it doesn't happen all the time....