i only be able to hash at around 1400kh/s while mining in xvg i could get up to 18000kh/s. so what is wrong here?

Hi everyone, long story short that i have been mining on yiimp for verge coins. i have checked on electrum wallet on windows which stopped receiving coins for almost aweek now. it still stays at 290 coins, however when i check on the yiimp pool which has shown that i have got paid up to 600 coins already. So what is going on here? how can i receive the missing coins? Thanks