High sleep power consumption compared with LowPower library

[caradag]

Using Minicore sleep function with sleep mode SLEEP_POWER_DOWN on an Atmega328P (8 MHz internal oscilator) leads in my test to a current draw of 208 uA. In contrast, using Arduino LowPower library, it is 3.6 uA.

The LowPower command used is:
LowPower.powerDown(SLEEP_FOREVER, ADC_OFF, BOD_OFF);

If, instead, I go to sleep with ADC_ON, the current is very similar to what I get with minicore sleep. Therefore, I thought that Minicore was not switching off the ADC. However, powering it off with disablePower(POWER_ALL) before sleep does not change the current draw.

Does Minicore SLEEP_POWER_DOWN keep the ADC ON? If not, what accounts for the extra power compared with LowPower library?