Left analog stick not registering.

So I own an Elite controller and have put many hours of use on it. I would say I am a fairly clean person as well so the controller is in fairly good condition. There’s just one issue that I have with it and cannot figure out how to fix it. When I move my left analog stick forward it doesn’t register the full movement. What I mean by that is if I press it forward so I would move, it won’t move me in a full speed. This is a big issue in games like Overwatch and Halo where sprint isn’t a factor. I played with it for awhile on Apex Legends without noticing it because if I click the left stick in to sprint, it registers the full movement. I have even taken a look at the thumbstick in the Xbox Accessories App and in there it doesn’t notice a full motion forward. It registers a full motion left, right, down, in the 45 degree angles, but not the up/forward motion. Please help! Thank you!