There is literally no information here, so how do you expect anyone to give an appropriate answer?
Do you have a voltmeter? Do you understand how to use one?
Have you measured incoming voltage?
Is the skybox connected to a battery? What is the voltage of the resting battery bank?
Did you boot the the skybox on battery power only?
In which sequence did you switch breakes on, ie: batteries first, panels second, AC input third?
Did you follow the commissioning procedure step by step? At which step are you detecting a problem?
I don't think this board has any psychics, so you need to provide information that mortals can digest.