Hi Robert,
Here is how it works:
- The Display units that you set in the map properties control the units for X and Y coordinates that you see in the Edit Vertices tool.
- The Map units in the map properties control the units for Z values that you see in the Edit Vertices tool. This is read-only and comes from the map’s coordinate system (see the information bubble in the screenshot below).
- One thing to note: if the layer has a vertical coordinate system defined, then the Z coordinates will derive from its vertical unit. If there isn't a vertical coordinate system defined for the layer, then the Z coordinates will default to the projected coordinate systems vertical unit (which will match the projected coordinate system's linear unit).
In the screenshot below, I’ve tried to illustrate a possible example where the XY units may not match the Z units. In the screenshot, the layer’s XY coordinate system uses feet as the linear unit, so the map’s display units have been set to feet, which controls the XY units in the Edit Vertices tool. The XY coordinate system of the map is WGS 1984 Web Mercator (auxiliary sphere), which uses a linear unit of meters, therefore, the Edit Vertices tool will display Z values in meters:
As far as incorrect z-values when you copy and paste - we are investigating a possible scenario where that could occur. Can you please provide me with more details about the coordinate system(s) (XY and possibly Z) of your layer and the map - as well as information about the map units and display units as discussed above?
EDIT: I know you have provided some information already, but perhaps some screenshots of the map's properties General tab and Coordinate System tab, as well as the layer's coordinate system tab will help.
Thank you,
Scott