Portal or Site Users do not see Activity History on their Accounts

Workaround: Use a Flow to Set Tasks and Events as Public

To make all Tasks visible to site users (depending on whether they have access to the Related To record), create a Record-Triggered Flow on the Event and Task objects. The Workflow Rules feature referenced in the original article has been deprecated — use Flow Builder instead.

Create a Record-Triggered Flow on both the Event and Task objects with the following criteria:

• Trigger: A record is created or updated
• Entry Conditions: Public equals False
• Action: Update the record — set Public to True

After creating the flows, note the following:

• You may need to update all existing Activity records by setting the Public field to TRUE manually or via a bulk update.
• You may also need to update the field-level security on the Public field to ensure the user's profile has read access.
• If an external user (site user) owns the Task, that user sees the task on the site regardless of whether it is marked Public.