WRND solar chargers review

Bad almost Non existing support and after sales service for very expensive chargers. Their WRND MPPT Solar Charge Controller, 12/24V, 120A switches off with low voltage warning and does not switch back on even though there is enough solar power available. It will only switch back on if you disconnect all power usage after a time has elapsed - meanwhile you are without power. No answer to emails to them. The system settings are locked by a password. Their manual is useless with no help. I am currently without any solution to this problem.