If you know that an audit has been authorised, however it is now showing as "In Progress" again, this is because a user has clicked the "Edit Audit" button.
When this button is clicked, the audit will be passed back to the original Auditor to edit and the audit summary table will appear as per the below. Here you can see that the audit has a Start and Completed date, however the Completed dates for the first two individual steps are now blank. The audit therefore needs re-completing.
To re-complete the audit, the Auditor simply needs to once again mark the first step of the audit as complete (after making any required changes), create any new actions resulting from any changes if required and mark the action plan step as complete (any previously created actions will have been retained). The Authoriser then needs to re-authorise the audit. It will then be marked as complete once again.