In Salesforce Lightning Experience, the Action button that appears in a Related List in Salesforce Classic may not be visible on the Lightning record page. This typically occurs when the Related List component on the Lightning record page is not configured to display the list view action bar. The issue does not affect Salesforce Classic, where the Action button displays by default.
To restore the Action button in the Related List in Lightning Experience, update the Related List component settings on the Lightning record page using the Lightning App Builder.
The Action button visibility in a Related List depends on the Related List type being set to Enhanced List. Follow these steps to enable it:
Notes:
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