You were gaining the tokens, but you were gaining so many that you were earning 100+, getting the effect, and resetting the counter to 0. The game doesn't show the number in green those times because it's seeing no change from start of turn to end of turn, just a quirk of the way the system is designed. Look closely at the numbers and you'll see that the opponent is having his wall reduced the extra amount.
The first example is Turn 7 where your attack reduces the wall by 9 rather than 6.
http://arcomage.net/?location=Replays_details&CurrentReplay=327374&PlayerView=2&Turn=7