TPS61256: tps61256 Vout error

I use tps61256 to supply power to the communication module. The maximum current of the communication module is 270ma, VIN = 3.9v, Vout = 5V. The schematic diagram is shown in Figure 1. The processor is mtk6763pcb, and en is connected to GPIO. See the attachment. The following problems occur during debugging

1、先加上负载，再使能EN，输出电压异常，测量发现低于Vin；

1. When the load is applied first and then en is enabled, the output voltage is abnormal, which is lower than Vin;

2、先使能EN ，再加上负载，输出5V正常；

2. First enable en, then add load, output 5V is normal;

3、先加上负载，同时在输出跟负载中间串个延时开关，电压就正常；

3. Add the load first, and string a delay switch between the output and the load at the same time, the voltage will be normal;

4、我尝试并联10uf电容在输出或者输入，但没能改善；

4. I tried to shunt 10uF capacitors at the output or input, but failed to improve;

请帮忙分析下原因？改怎样调整电路？电容为瓷片电容，电感资料见附件

Please help to analyze the reasons? How to adjust the circuit? The capacitance is ceramic chip capacitance. See the attachment for inductance data

SD60ID_Sim Board_P0_PCB_20190215.pdf

MPIA252012系列201408.pdf