Is this a Screen Controller IC issue?

I recently posted about an issue I had with my iPhone 5S after a screen placement where I'd get phantom touches in random areas of the screen and it would seem like sometimes pressure is being held somewhere on the screen. I was advised to get a new screen/digitiser so I did and upon installing it, it seems that the right edge of the screen (maybe the last quarter to be precise) is not recognising any touches. The installation went smooth and the digitiser cable clicked in nicely.

EDIT: Skip to edit part below.

Upon Googling the issue I saw a few mentions of Touch Screen Controller IC... now I have no idea what this is but it seems like it may be the cause. Could anyone confirm that this is a likely possibility? And if so, how hard is it to replace seeing as though I don't even know where it is. Lastly, should I try reconnecting the digitiser cable or is it not worth the hassle?

Thanks in advance.

Chris.

EDIT: Just saw a video of how to replace the IC and it's something I definitely WON'T be attempting. The one thing that still confuses me however is before I installed this screen, the previous screen (despite its phantom touches) did have a working right side? Any suggestions why?

2ND EDIT: Just noticed that I can get the right side of the screen to register my touch if I place more surface area on it such as the center of my thumb as opposed to the tip... not sure if this will help anyone diagnose the problem but at least I can now enter my passcode and get into the phone at least.