If the original issue was related to the cable, it could be the cable again, or even the connector (I know those wide Samsung main cable connectors can be fussy to connect properly and are damaged easily because of this.
But the fact that it's a single line across the display makes me lean more towards the display. Localized touch screen issues in my experience are almost always the display. Digitizer damage is not always visible, and could be caused by some minor bend.