I don't think we could ascertain much from the provided photos without a bit more information. I'm not an electronics repair expert, but if this was my keyboard, I would follow the trace from the last key in the column all the way back to the controller. Which I would check for continuity from the controller pin to the column. When you say they all register when you press just one, that sounds like it's a short. A closer visual inspection for a missing/loose component? Liquid damage shorting something connected to that trace?
However, then you say the column DOESN'T register anything yet the LEDs light up? Is it sporadic, or does it have the exact same behavior every time?
Anyway... I would definitely start by following the trace carefully (might run through to both sides of the board through a VIA at some point) all the way back to the controller. Speaking of, perhaps a better closeup shot of the controller from directly on top. It's fairly hard to tell if any pins are loose or bridged from a photo, but I definitely cannot tell from the angle you provided.
Test, hand-wire it:
https://docs.qmk.fm/hand_wire
(and not hotswap so often)
"the whole column activates".. i would first check the diodes. most multimeters have a diode measuring function, but measuring in circuit might not work. worth a try though (just make sure to get the polarity right).