Multiple citations from the same author

The setting you would want to change is in the style.

In EndNote you can go to Edit > Output Styles > Open Style Manager > locate the style you are using > Click Edit > go to Author Lists under Bibliography > here change the setting under For Subsequent Works by the Same Author change the setting to “Print Author List as defined above”. > go To File > Save As > (EndNote will not allow you to change the existing style in EndNote but will always apply the change to a copy of the style) Click Save to save the changes to a copy of the style > close the style window.

You would then switch styles in Word using the steps on our website.

https://support.clarivate.com/Endnote/s/article/ka1390000004b6QAAQ/EndNote-Changing-Output-Styles-Within-a-Document?language=en_US