NBitcoin and Mnemonic Standards
The mnemonic standard is BIP 39, and that is not the problem. The problem is the derivation paths.

Exodus, Jaxx, Coinomi, and many other wallets use the BIP 44 specification for deriving keys. This means the m for those wallets is actually the key at the path m/44'/0'/0'. However in your code with NBitcoin, you are using direct BIP 32 paths, so your m is actually m. So in NBitcoin, your keypath is actually m/0/0 but in other wallet software, the path is m/44'/0'/0'/0/0