Sabvoton 96120 start up issue

I am running a sabvoton 96120 and generally everything is fine, except for 1 odd issue. When I 1st turn the bike on there is a period of about 30 seconds where it runs at about 1/4 power. If I turn the bike on and let it sit for 30 seconds the power will be 100% when I give throttle.
Does anyone know why my controller has this 30 second time after start up where the controller is not giving full power?
I have done all the calibration re motor phase angles.