This can quickly be fixed. Follow these steps to clean up broken charts that were created due to incorrect amount values being added to the Opportunity history:
Contact us with the record ID(s)
We will manually remove the wrong values from our databases
Delete the wrong record(s) from your Salesforce instance
Re-create the wrong record(s) with the correct values
The records must be deleted and re-created because the wrong amount will be stored within the Opportunity history. As such, they will return if Weflow needs to re-process your data, e.g., because of changes to the fields you used or new analytics and charts we may provide.