Right stick has reduced y axis sensitivity

Im not sure what could be causing this, but I noticed it in R6 when trying to aim up, it seemed way slower than it used to be, I brushed it off as nothing, but when using a test program on pc, my y axis only has 65-70% of its ‘sensitivity’ when moviving the stick up, and 60% when moving it down. Obviously this is what caused my issue with sensitivity. With the way the sticks are made, could this be fixed? Is it a bit of dirt in the mechanism? Anyone got any experience with an issue like this on a controller stick?