Seems like there is no problem with rakeback. I have just placed few bets and the rakeback amount was increasing normally as it should be for my rank. Usually all crypto coin have 8 digits after the decimal point. But at wolf.bet rakeback page all coins have extra four digits, in total 12 digits after the decimal point.

So whenever we place a bets the rakeback amount also get added with those extra four digits. Maybe you are ignoring those amounts and making wrong rakeback calculation.