Atmega sleeping: power consumption lesser with 10uF capacitor

[sineverba]

Hi to all,
background: spare Atmega328 @8MHZ / 3.3v, BOD disabled.

2XAA feed about 2.70 when full charge. Voltage divider to read them, power to a booster to 3.3v.
Sleeping for all time, every 10 minutes read a SI7021 and sends volt+temp+hum to gateway via NRF24L01 (time, about 5 seconds).

So, all is powered via the booster.

This is the schema, ready to print the PCB:

f I remove the 10uF capacitor placed near the batteries, power consumption when sleep is about 1mA.

Too high for a powered battery!

WIth that cap, power consumption on sleep is 78uA (microAmpere).

Is it normal and... is it ok???

Thank you very much!