LM5176: LM5176 efficiency and stability issues

We changed the feedback resistance to: R11=100k, R14=475K. Our Vin=24V /Vin=12V ，My customer’s goal is that when the input is Vin=24V/Vin=12V, the efficiency can reach more than 95%（vout=24V@3A)  the data sheet, this value can be achieved）But when I was testing, I found the following problems：

1.Insufficient efficiency

2.Abnormal waveform

• When I set the voltage nominal value to 24V，Inductance does not change,The output capacitance is 684uf (4.7uf*5 ceramic capacitor +330uf electrolytic capacitor,We estimate ESR to be 2 m ohms) ,The MOS is: BSC093N04LS.We use the calculation tool to get the result:

We set up according to him, but the result is not ideal.I found that the efficiency can reach 96% at 24 to 24@3A, but at 12 to 24@3A, the efficiency will drop to about 92%, and the SW waveform is abnormal

• When I set the voltage nominal value to 12V，Inductance does not change,The output capacitance is 684uf (4.7uf*5 ceramic capacitor +330uf electrolytic capacitor,We estimate ESR to be 2 m ohms) ,The MOS is: BSC093N04LS.We use the calculation tool to get the result

when 24 to 24@3A   The SW waveform is abnormal and the efficiency drops to 94%

when 12 Vto 24@3A   The SW waveform is abnormal and the efficiency drops to 90%

So I have the following questions:

1. Why is the SW waveform abnormal? How should I set my voltage normal to 12/24V?
2. How should I set up to make my efficiency higher? (I think the switching loss caused by the abnormal SW waveform is too much, but I don’t know how to make the SW waveform normal)
3. How should I set my crossover frequency(The data sheet and the calculation tool indicate different values）? What will it affect my system?
4. Which parameters are related to efficiency and stability, and how should I improve (I know the crossover frequency, ESR, compensation device will affect, but what is their relationship? I hope to understand)

thanks

BR

jeson