Some updates - this is happening randomly also when just rebooting device. Sometimes it uses 5-7% CPU, sometimes ~25-30.

After fresh restart (with reboot)

Tasks: 100 total, 2 running, 98 sleeping, 0 stopped, 0 zombie
%Cpu0 : 22.1/4.1 26[|||||||||||||| ]
GiB Mem : 20.1/0.2 [ ]
GiB Swap: 0.0/0.0 ...

Hi,

I am using pico ultra w with buildroot. After boot CPU usage is around 7%.

top - 00:18:07 up 21 min, 1 user, load average: 10.19, 9.97, 7.55
Tasks: 93 total, 1 running, 92 sleeping, 0 stopped, 0 zombie
%Cpu0 : 2.9/2.9 6[|||| ]
GiB Mem : 20.6/0.2 [ ]
GiB Swap: 0.0/0.0 [ ]

PID USER PR NI VIRT ...