Magnet is PoS/PoW mining with a 1 in 2 chance occurrence of either. So masternodes receiving 50% of mining rewards also have a 1 in 2 chance of receiving either a PoS or a PoW reward.

PoW = 200 Mag so masternodes receive 100 Mag when they win PoW.

PoS = coin-day * 7% / 365 so masternodes receive X Mag depending on the staking amount.

The screen above shows that your masternode received 5 rewards. 4 of which are PoS and one is PoW. Now this is like flipping a coin, eventually you will end up with around 50% PoS and 50% PoW.

One more important thing, verify that you have disabled staking (staking=0) in your configuration file as this could potentially reset your rank and you would lose a chance at an actual PoW reward whenever your coin stake wins the block. PoS rewards are typically small as the network supply is still small too but we can easily see a day where staking rewards will outperform PoW rewards.