When using MobaXterm you should not save your password when prompted to do so. MobaXterm will save your password, and then inadvisedly try to use that as your “Verification Code:”, which means that when you first connect to the cluster in MobaXterm, you are prompted for “Password:”, and which you will need to press to be prompted for “Verification Code:” If you accidentally saved your password, you can remove the saved password by the following steps.
1) In MobaXterm, go to “Settings->Configuration”
2) On the next screen select “MobaXterm Password Management”
Once these entries are deleted, you should be prompted for “Verification Code:” when you connect to the cluster via MobaXterm.