Your NiceHash wallet is not a blockchain wallet, but a regular wallet that uses certain defined Bitcoin address for deposits.
If you check this Bitcoin address on the blockchain, you will see that the transactions do not match the ones being executed in your NiceHash wallet. This is because we do not issue blockchain transactions for internal movements of coins (mining payments and order payments), because each blockchain transaction requires a certain amount of transaction fee and several minutes or hours for confirmation, while our internal transactions are completely free and instant. Therefore, it does not make sense to use blockchain transactions for our internal accounting.
Be very careful when checking your outgoing transactions (withdrawals) on different blockchain monitoring sites. “FROM address” is not the same as your NiceHash account deposit address!