I have the same (65t Elite Sport), and once in a while I do get a momentary crackle here and there, also when it's in my pocket. It seems to happen mostly when I'm moving in a way that could be putting more of my leg in contact with the phone. I have also, however, been able to leave my phone at least a few meters/yards away and not have any issues, so it seems to be related to the water in my body absorbing some of the signal. You might try to use a different case or move the phone to another pocket that is not as close to your body.
Otherwise these headphones are really wonderful.