Request Workfront to provide a feature to optionally clear field values where a field becomes hidden on the form. It may be of value to retain hidden values in some cases so a checkbox option on a field to Clear Value when Hidden would work.
The issue occurs in cascaded drop down lists where higher level list options are changed, but lower level lists retain the data even though not displayed. These get replicated down to the Cosmos parameter values table leading to confusion in reporting. It also occurs for other form fields where the value of a field A determines the visibility of field B. If the field B value is set, then the value of field A is changed so field B is now hidden, the value of field B is still presented in the object's parameter values.
