To amend the activity field in the case history, follow the below steps:
Go to User Profiles in the Authorisations tab.
Under the History Screen section, select the option to allow users to amend item activity.
After you've enabled this, ensure the Activity column is visible in the Case History. Right-click the relevant history entry and select "Amend Activity" from the menu that appears.
Note: If the Activity field is greyed out in User Profiles, this needs to be updated by the Default user, please ask a question in the MyAccess Portal Digital Assistant and ask to "Speak to a human" to be put through directly to our support team.