Thank you for contacting us, and I'm sorry to hear about the issue you're experiencing here. I'm not sure what happened with your password in mSecure 5, but we don't have any known issues that cause this sort of behavior. However, you should be able to migrate your data in from mSecure 4 by resetting your mSecure 5 account, and then reinstalling mSecure 5 app.
Before going through the process below, please stop and tell me if you migrated your data into mSecure 5 some time ago. I'm writing this under the assumption that you installed mSecure 5 a very short time ago due to the problems caused by the latest iOS update.
After the account is reset, the migration will be triggered as you go through the sign in process in mSecure 5.
To reset your account, follow the steps in this support article: https://support.msecure.com/en/support/solutions/articles/36000064228-account-reset
IMPORTANT: Do not delete the old mSecure 4 app from your device. If that is done, the data stored in the app will be lost. Also, your mSecure 4 data is not connected to your mSecure 5 account in any way, so performing the account reset will have no effect on the data stored in the old app.