I'm not exactly sure how to title this question, but the situation will make sense after this explanation.
I was playing No Man's Sky yesterday, and noticed that randomly the cursor would start to move to the left. The current controller I use is not more than a few months old, so I thought maybe it was the game. I couldn't seem to accurately reproduce it either, so I kept working at it. Finally, I found a way to 100% reproduce the issue each time;
If I move the left stick directly to the right, the stick will leave a ghost input to the left. However, the catch here is, the L2 button will accelerate this issue. Holding down L2 will indeed move the cursor to the left. I tested this in Overwatch as well. As soon as I press the left stick to the right, I hold down L2, and my character moves to the left.
I've never experienced something like this. I've been very gentle with the controller, haven't dropped it or thrown it around or anything. My research on Google only found information on PS3 controllers with unrelated button issues.
TL;DR - If I press the left stick to the right, release the left stick, then press and hold L2, the controller sends a strong "move left" signal, in addition to any other function assigned to L2.
I have already ordered a new controller, but I don't think I need to scrap this one entirely. What could I do to try and salvage this controller?