HA high cpu, but nothing in "top"?

Hello,

running latest home assistant on bare metal RPI4 (buster-lite).
I noticed that my RPI was more ore less “slow”.

#1. I stopped HASS --> CPU OK
#2. I Started HASS --> CPU to +/- 30%

However, running “top”, I can’t see any noticable CPU activity:

Is there an easy way to find out why/where/what is consuming my CPU?

kind regards,
Bart