High power consumption on SYSTEM OFF - nRF52810

Hello DevZone,

I have made some custom boards with Laird's BL651, wearing nRF52810 chip. I was testing the power consumption and I can't get it down to uA level in system off. 

The board drains 2.5mA minimum when in system off, with a gpio sense input for wake up.

The board consists of a PDM microphone, 2 LEDs and a tactile switch. I checked the voltages from the respective GPIOs while measuring the current, and they were fine. The microphones stays off if there is no clock source and LEDs were off.

I also tried running the chip with no soft device present.

Is this expected since I'm not using the recommended 32.768KHz external crystal?

Thanks in advance!