Why is my anolog replacement never central

Hi all

First time asking a question on here so here it goes.

I've recently come across a broken controller that I'm repairing. The issue is stick drift and I've decided to change the anolog and re solder a new one on. Everything has gone great and the repair was a success. However, whenever I tested it on Gamepad Tester and the anolog is not central. It's always rather 0.4 to the left or right.

Is there a way to get the anolog closes to the centre as possible or is this impossible?