Headphone jack adapter not working

I purchased a replacement headphone jack adapter for my Iphone 7 a few weeks ago, and it was working fine until recently my headphones began popping/making cracking noises whilst playing music. The problem just seems to be getting worse, with music almost inaudible, and I have tried different headphones (all apple) and the problem persists. I have also tried the adapter in another Iphone and the same issue occurred. How can I fix this?