Korennya, have you been mining lyra2rev2 ? If yes then I (and many others here) had the same problem. MultiPoolMiner reported 0.0005BTC/day, but I was only getting half of it. Now I'm running xmrig + ccminer (lyra2z) only and my earnings from the last 24 hours are much higher (around ~0.0005BTC/day). There's some kind of issue with lyra2rev2, ccminer and this pool. I believe no one has found a solution yet.
That may be part of the problem but they have also added algorithms from other pools. I've found a lot of there missing funds.