DCDC(LT8650S) no-load inductance is very hot

I used LT8650S, 24V input, 12V output (rated current 2A). After the board is electrified, the no-load inductor L9 is extremely hot. The switching frequency of 2M and 400k has been tested.(6 layer board).The waveform at SW is also bad, not square wave, and the voltage at VCC, VC1 and VC2 is 3.41v. What's the problem?It doesn't feel like it's working properly.

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