You can check the multibit log file and see if you can find an entry like:
If you get that, your only option is to use an offline version of the iancoleman website... put in your seed, change the "Derivation Path" to BIP32 and set the client to "MultiBit HD"... path should be m/0'/0
That will show you the main receive addresses/keys for your MultiBit HD wallet... you'll need to hunt through them one by one to find your coins... (could be hundreds of addresses to check depending on how many transactions/addresses you used in your wallet)... THEN, you need to set the path to custom and use m/0'/1 and look through all the change addresses associated with your wallet as well... (depends on how many transactions you sent from your wallet as to how many you'll need to check)
Once you find the addresses that still have coins... you can import or sweep the private keys for those addresses into the wallet of your choice...
If you haven't found the specific BTC address you sent money too, then either you need to show a lot more addresses on the BIP39 site, or that address is not associated with your account... if you look at te specific BTC address on a block explorer like blockchain, does it actually show the coins?