Sabvoton controller issue

Hi all,
Sabvoton SVMC 96120, have strange issue with throttle response.
Sometimes it turns on normal and can go ride hard, but sometimes it turns on and throttle do nothing)))

Is this hardware issue or software config?

Not exactly an answer but usually when it used happen to me I would notice controller led light blinking signaling some error.
In my case it happened due bad connection in wiring.

BTW there is that delay after which you turn on controller and it starts to function after a few seconds.