Left joycon not detected on console when in handheld mode

I dropped my Nintendo Switch two days ago and my left joystick got damaged, but I decided to upgrade to the GuliKit Hall Sensing Joysticks to extend the lifespan of my joycons.

I followed iFixIt's repair guide, as well as buying a Nintendo Switch tool kit to deal with the screws inside the joycon.

All went well, but I accidentally took out the ribbon for the charging rail on the joycon instead of the ZL button (as the guide suggested me to remove the midframe of the joycon to make it easier to replace the joystick).

After replacing the left joystick, it detects the joycon, but it won't recognize my left joycon is attached to the switch. After browsing the forums, a lot of people pointed to the charging rail being faulty, and I had thought maybe I accidentally broke the ribbon cable. So then I bought a replacement charging rail and replaced the charging rail. However, the specific ribbon cable (the one near the joycon) that I had mistakenly pulled out is still being used even after replacing the charging rail. (The ribbon cable connecting to the PCB of the charging rail).

Is it possible that it's a loose connection? I've tried making sure it's slotted in correctly many times but it won't detect it's connected.

I've tested with another pair of joycons for the left side and can confirm that the rail on the console works as it can detect my other left joycon, not the joycon with the gulikit joysticks.