Seeeduino powered by a DC supply from a DC-DC converter

Hi everyone,
I am using a seeeduino XIAO and I have flashed a code to read the temperature value from the temperature sensor LM35 connected to the pin1 of seeeduino. Now, I want to power the seeeduino and temperature sensor using the output from a DC-DC converter AP62300WU-7. The circuit diagram of the whole circuit is below:

when i connected the seeeduino, the yellow LED is blinking. it was not blinking when connected to the laptop. does anyone know why this is happening or what this indicates?

Hi Gourie_Sankar,
What is J1 connected to?
What is the function of the circuit consisting of C1, C2, C3, D1, and C4?
How many volts is Vin of AP62300?
Does OUT1 stable 3.3V even when XIAO is connected?