Joysticks jumps around after replacements

I've replaced joysticks on two controllers now and ran into the same issue both times.

Simply put, the joysticks wobble around from one direction to the other constantly, and one stick won't work aside from the LS click. All solder connections are working(checked continuity), no burnt off pads and no bridges as far as I can see.

In the first controller, i swapped one stick and it caused this on both. On the new one. I swapped both and both are affected, but one stick doesn't work at all.

LS is a third party replacement stick and doesn't react to movement. Jumps from left up to right down.

RS is a harvested stick from a broken controller and reacts to movement, but jumps from left to right.