LNK306DN for ESP32 always restart

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I am trying to make a power supply for ESP32 using LNK306DN with one diode rectifier 1N4007.
I want the output power suppy is 6V then I use LM1117 to get 3.3V before connect to ESP32.
But I have a problem, the LNK306 always restarts.
I measured the output drop to 4V then returned to 6V.
I think this is lacking current for ESP32.
I tried with another power supply with a voltage of 3.3V 300mA can boot.
And I have tried replacing EC1 & EC2 with 2.2uF/400V but the results still same.

Is there something wrong with my circuit, please advise.

Thank you

LNK306DN.png171.68 KB

There a several possible reasons for this to happen.
Looking at your circuit I cannot see the preload resistor required as per page 7 of the datasheet document https://www.power.com/sites/default/files/product-docs/lnk302_304-306.pdf.
Please study the power supply requirements during different stages of your actual equipment booting process.
Then, connect a variable resistive load to the output of the power supply to convince yourself that it is doing what it was designed for.
Only when both sides (load and PSU) are in agreement as DC levels and time-domain transients please connect them together.
Best Regards,