If you've entered the seed in your wallet, all it shows is an empty wallet. It means that your seed is incorrect, has been incorrectly supplied, or you have stored it incorrectly. Or it is the seed of an empty wallet
Not necessarily: the derivation path could be the problem, a different path gives different addresses. It's not unlikely that "Ninki" used a different path than Electrum.
Ninki uses a 2 of 3 multi-sig, probably importing the seed on electrum will just show nothing.
As I posted above, op should try to import its seed using the multisig wallet of electrum using his 12 offline keys, 12 online keys and its xpub as the requirements in ninki recovery tool.
As I don't have experience of using a multisig wallet, so I can't help much.
But I guess there's no harm of trying, right. Assuming you have 12 offline keys, 12 online keys and its xpub as the requirements in ninki, you may try to do it on electrum
-New/Restore
-Multi sig wallet
-choose 2 of 2 cosigners and signatures
-i already have a seed
-enter your offline 12 keys
-check if the xpub you have is the same that displayed on electrum
-enter cosigner seed, here enter you online 12 keys
-click options choose bip39 seed
-click the "detect existing account" if something shows, if none choose enter this derivation path m/0.
Check if it works, though I'm not sure. Correct me if there's something wrong though.