Screen unresponsive after charging port/headphone jack replacement

A while ago my iPhone 5C was a victim in a water based incident. It luckily survived, though I had to replace the screen and the battery. Since then it is worked flawlessly, apart from the fact I'd never get any service. Today however, I finally got round to changing the antenna, but swapped out the whole assembly including the headphone jack and charging port. I put the phone back together, booted it there was no issue there apart from the fact the screen is now somewhat unresponsive. It isn't entirely dead but swiping to unlock is done with great difficulty and now it's like the touchscreen has a mind of its own, which bizarrely was never an issue prior to replacing the part. Any suggestions as to what's going on? If I can avoid having to change my screen again then that would be great, but if perhaps there's been some collateral damage to the digitiser in the repair process, could anyone tell me where that might have occurred?