S2lP error code "LOW BATTERY Indicator"

[CKim.18]

I have reference H/W design by X-NUCLEO-S2915A1.

It has still have "IRQ_LOW_BATT_LVL" and not send TX data.

-Pin1, Pin7, Pin10, Pin15 is 3.3V Level.

Could please let ms know if you have any recommend my check point...