Gains Randomly changing?

I have 2 Kicker comp Rs and a soundqubed amp with a bass knob...every once in awhile whenever i turn my car on it’s almost as if it changes the gain. for example i’ll have the knob all the way up one time and there will be no clipping but next time i turn my car on the knob all the way up is way too loud and clipping? is there any fix to this problem? i haven’t heard of anyone else having it anywhere else