Power factor down after solar connection
Solar panels can supply only real power, not reactive volt-amperes. If the factory supplies much of its own real power from solar panels, that reduces the real power received from the utility but not the reactive volt-amperes. The natural result is a low power factor at the meter. The remedy is to install a power factor compensation capacitor bank. That can be done as part of the solar panel power conversion unit, but was apparently not done in this case.