Issue
When using the action 'Set Field in Current Item' or 'Update List Item' in Nintex Workflow for Office 365, it automatically sets the list column that has the data type Multiple line text to blank, even though this column is not part of the field that is being updated, in the action configuration.
Resolution
The root cause of this issue is because the Multiple lines of text column has a field 'Append Changes to Existing Text' that has been set into 'Yes'.
- If this is not the business requirement, then set the 'Append Changes to Existing Text' into No.
- If this is the business requirement, then make sure that the action to update list item is configured to set the value of the Multiple lines of text column to avoid overriding into blank value.