I've had the same Diamond IV player go AFK in ranked games four times in two weeks

For 2-3 minutes at a time, then they come back, CS a bit, go AFK again, and repeat all game.

It's the exact same thing every time. They spend probably 1/3 of the game AFK, but they aren't getting hit by leaverbuster because they're still 'playing'.

Can we please get harder crackdowns on this?