Left click button (L3) doesn’t work after replacement

I ordered a left thumbstick because on my old was the left click button (L3) didn’t worked. It was clicking fine, physically, but on the system it didn’t register as clicked, both in game and on the controller test option in the settings.

So after I changed the left thumbstick, it is same as before, the click button doesn’t work.

Any suggestions on what that might be?

Many thanks!