Although I did use Multibit HD in the past, I can barely remember how the user experience was....so correct me if I'm wrong here.
Multibit HD used to give users the ability to create different wallets/accounts (not to be confused by addresses). Right?
If so, then it's quite possible (a big maybe) that the funds are in one of those wallets
You can try to restore the wallet the same way you did, but instead of leaving the default derivation path (as shown here in step number 2.b[1]), try to change the last number in it to 1, 2, 3 etc. and see if you manage to find your funds.
[1] https://bitcoinelectrum.com/restoring-your-multibithd-wallet-in-electrum/