Jamal,
There are a lot of unknowns about your network, how you are configuring your project, ArcPad/Zeno Field, etc. You had mentioned prior that you are modifying the GPS datum in Zeno Field, which is not recommended as all transformations are handled by Zeno Office/Zeno Office on ArcGIS. Also, what coordinate system is your GPS reference network sending the corrections in?
I would highly recommend some level of training (on-site or web-based) as I do not experience any of the difficulties that you have to date. When I connect to a local real-time network (RTCM3_IMAX mountpoint), receive RTK corrections to 1 cm and check into a control monument with established coordinates I check well within the GNSS accuracy stated by the GG03.
If you set the GG03 up on a known point, are receiving RTK corrections to a phase-fixed 1 cm solution and are not moving while storing 3 separate points, all three of the X, Y, Z values of these survey points in Zeno Office/Zeno Office on ArcGIS should be in the centimeter range. If not, you have a configuration issue.