Thank you for contacting us, and I'm sorry for the issue you are experiencing. I just re-checked this functionality in the iOS version of mSecure, and nothing went wrong when I added a second password field to the Logins template in my real database. I went to the Settings, tapped Edit Templates, tapped the Logins template, then added a password type field called "Second Password" and saved the changes. After I did that, all of my Login records show the new field only when I edit a record and add data to the new field, so something is going wrong here, but I don't what it could be.
Do you remember if you did anything after you added the field to your Template? What should have happened is that your first password field should still be named "Password," and the second field you added should be named "Second Password." The "Second Password" field should not be displayed in any record's detail view until you add data to the field by editing the record. First, did you first change the name of the original password field? If so, what did you change it to? Also, is the original password field now named "Second Password" in all your Login records?