Program not running when ST DISCO is powered on battery

Hi all,
I’m experiencing a problem when I power the ST DISCO board with the power boost shield 500, I noticed that either the program stops unexpectedly or it cannot recover from sleep.
At the contrary, when the device is powered via ST Link it works properly.

The application is running on mbed os 5.15, it reads onboard sensors data every 10 seconds and stores it in lfs, then every 10 minutes all data stored is read and sent over wifi to an external MQTT broker.
What happens when it runs on battery is that it starts collecting data from sensors but then after 10 minutes, when it’s time to read from lfs and send it over wifi it stops working.

Any clue anyone?
Thank you in advance,