Left Stick is dead after repair shop replaced usb c port

Hi guys, I took a switch lite that was working fine but it wasn’t charging, to a repair shop, and they fixed it by replacing the usb c port. I got it back in early December and hadn’t used it until I gave it to my girlfriend on Christmas, but then she noticed that the left joystick was completely dead, but also her in-game character would slowly creep down and slightly to the left. She is still playing her game fine with another joycon, but when she is not moving anything, the character still moves slowly down and to the left (playing Animal Crossing).

I was wondering if I could just open up the device and maybe reseat the joystick cable? Or does this issue sound like the repair guy might have messed up something a bit too complicated for me to do?

My only experience with repair is replacing an old macbook battery and I have an iFixIt pro tool kit.