nicehash is not a mining pool. is a hash market platform. when you join an algorithm you are essentially selling your hash to buyers who buy hash to mine coins with that algorithm in other mining pools.the prices are determined by the buyers and the average payment price has the standard, payment per share PPS -4% that nicehash keeps. in a few words the profit is the average price of the buyers -4%. it is better to go to another mining pool that does not have so many reservations.
What does nicehash do when there are no buyers?
From the mining algorithm, it selects the most profitable algorithm, but pays you in bitcoins or other coins that you choose. When Ethereum was the most popular coin for mining, the profit was the same, but now, due to constant switching algorithms and rapid changes in coin prices, the profit may differ.