The circuits on amps that say "clipping" don't actually sniff out a clipped waveform, they're just turning on at some voltage selected by the manufacturer as their maximum.
That said if you are hearing audible distortion you're definitely over driving that amp and either you don't have adequate battery/alternator to feed it or you have poor/weak power or ground connections into it. Simplest fix would be to just turn the knob down a bit before turning that "clip" light solid.
Based on the Amp dyno video by BigD I thought my JP23 had an extremely accurate clip light. You can slow motion the video and see the bass knob light comes on a hair sooner than the Amp dyno's light.