The Pivot Orientation will change depending on the current selection may it be objects, vertices, edges, polygon faces etc.
You can adjust the Pivot Orinetation by adjusting the Reference Coordinate System as per attached image.
In Polygon Face mode try switching from View to Local and see if this resolves your issue.
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Technical 3D Graphic Artist
Autodesk 3dsMax 2015 - Service Pack 4
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