My iPhone 6 - 64gb space gray have a problem with clicking sound at the bottom right part of the display.
Yes it is on warranty. I buy this from Movicel shop in Luanda, Angola. So let me know where I should give this for to check.
Last time I noticed something like that on my 6, I noticed that the screw at the bottom right was a bit loosen. Once I screw it back using the appropriated screw driver, the clicking disappear.