PSM example program seems to consume high current in nRF9160 DK.

I'm measuring the current consumption of udp_with_psm program reading this post, and the current is very high. why?

https://devzone.nordicsemi.com/nordic/cellular-iot-guides/b/hardware-design/posts/measuring-psm-idle-current-on-the-nrf91-dk?CommentId=f9c4d469-0bfe-48f6-9ad5-118da9078a60

Modified points compared to the udp_with_psm in the above post

- Modem FW: v1.0.0

NCS tag: v1.0.0

- Use a LTE-M SIM which is not iBasis one. eDRX and PSM seems to work with the SIM.

- fixed code

error:
	freeaddrinfo(res); // THIS IS REQUIRED
	printk("Finished\n");
	(void)close(client_fd);
}

- change PSM setting

<prj.conf>

# 1 minute interval
CONFIG_LTE_PSM_REQ_RPTAU="10100001"

# 6 sec for idle
CONFIG_LTE_PSM_REQ_RAT="00000011"

- change host and port

// UDP test
#define HOST "8.8.8.8"
#define PORT 53

With this program, the floor current is 29 uA. Also the DK seems to generates a high current spike every 1.28 sec.

Why a current spike is generated every 1.28 sec?

The message is sent in the configured interval, 1 min.