You will want to check the Page Number setting in the style you are using.
The style might be set to Show the Full Range of Pages.
You can change the setting Don’t Change Page Numbers.
In EndNote you can go to Edit > Output Styles > Open Style Manager > locate the style you are using > Click Edit > go to Page Numbers > make the change 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 can the use the new style in your document.
If you have trouble of need further assistance then contact Technical Support:
1-800-336-4474 option 4 then 1