Vendor confirmed the problem
After several emails to Xantrex Tech support, I found out that there was a second control panel on the top of the inverter. This panel was not viewable due to how the inverter was installed. After some work I was able to see the panel.
The power button on the inverter's control panel was in the "on" position which disabled the power button on the remote control panel. Once the inverter's control panel power button was put in the "off" position the remoter panel power button was fully functional.
The picture shows the Inverter's control panel (bottom of picture) and the gray power button in the "off" (raised) position