In-game slow response time

Hey, for the last month or 2 I have been experiencing slower reaction time. I know it is usually ping related, but my ping is 3-5ms higher max (if at all). Another interesting thing is, that if I play champ like ez, sometimes I cant make full combo (the game wont register it). For example W wont cast at all. Or a visual bug, where his q deals dmg to a minion and yet i see it go further. It is really annoying and makes the game unplayable (especially animation canceling and kiting).

Edit: I play on ethernet and I have already tried the client repair tool.