MP2617H charger

I’m testing the MP2617H charger on the EV board and my own PCB.

I connected the battery and confirmed that charging and output worked well.
However, momentary blackout occurs when the 5V DC adapter is connected.

On the load side, the MCU and various sensors are connected, and the system is down and reset due to a momentary power failure.

What could be the reason?

Is there anything else I should do to prevent this?