Any idea what could be causing this? One click shifts up four gears, downshifts fine. Shimano 105

Any idea what could be causing this? One click shifts up four gears, downshifts fine. Shimano 105

Any idea what could be causing this? One click shifts up four gears, downshifts fine. Shimano 105
byu/Militant_Dilettante inbikewrench

by Militant_Dilettante