Both analog sticks not working after replacement

A friend of mine asked me to repair his Switch Lite for sticks not working. He claims they had intermittent issues and drifting. I didn't test them prior to repairs (should have). I replaced both analog sticks, both left and right. Upon reassembly, neither stick works as it should. I tried calibrating them, neither will respond to tilt/push. In the button test screen, both with register "L" & "R" upon pressing them down.

Has anyone else seen this type of error before? I can't find any other cases like this.

Lastly, before I get the "have you tried calibration" response: yes, does not work, sticks don't register movement. I have reseated the cables. I have inspected all cables, none appear damaged, torn, etc. This has me stumped.

Edit: I have since tried testing with the game slot/audio jack plugged in. Symptoms remain. I also tried cleaning the board very well. Symptoms remain.