SEN0609 (C4001) It burns after a month of use

Hello

I'm testing with a SEN0609 C4001 mmWave Presence Sensor 25m. It works well for my IoT application with batteries.
The problem I'm having is that after a month, the voltage regulator burns out.

The battery is 4.2V, and an MT3608B is used to maintain 5V, keeping the voltage at 5V very stable.

The AO3404A transistor is also used to short the GND that powers the radar.

Here are the circuits:

The radar is powered by 5V_RADAR+, and the GND is connected to OUT-DIS.

The UART is 3.3V.

The radar works, shuts down correctly, I can initialize it, and read speeds. The firmware works perfectly.

Obviously, the problem is with the power supply.

I could see that the board has two 1.8V regulators. The code qHGdf or 9HGdf doesn't look right. Does anyone have the code for this voltage regulator?

Is there any internal circuitry?

Any suggestions?

I hope you can help me.