/diy/ - Do It Yourself

Look for some insight on why the buttons on my PCB aren't working. I have two wires coming out of the OK screw terminal that I'm using to test with. When I connect them, nothing really happens on the LCD (it's supposed to display a menu change). When I clip them together and probe ground, I get a very noisy signal. Sometimes it seems like all buttons are being triggered at the same time (menu frantically cycling around). I cannot reproduce this problem deterministically. I am debouncing the buttons in the firmware. I had this exact setup working on a breadboard before soldering up the PCB. Any idea what might be happening here? Many thanks in advance (also pls no bully, I'm new)