I am observing the same thing. This can be easily fixed by setting the max frequency manually; https://www.incertum.net/post/2024/armbian-cm3588/
I checked `cpufreq-info | grep "available frequency steps"`
And made this to set the correct speed for all the cores on the RK3588 NAS KIT
# Little cluster (A55 cores: cpu0–cpu3)
for c in 0 1 2 3; do
cpufreq-set -c $c -g schedutil -u 1.80GHz
done
# Big cluster (A76 cores: cpu4–cpu7)
for c in 4 5 6 7; do
cpufreq-set -c $c -g schedutil -u 2.40GHz
done
Now running `watch -n1 "cat /sys/devices/system/cpu/cpu*/cpufreq/scaling_cur_freq"` together with `for i in $(seq 1 $(nproc)); do yes > /dev/null & done` shows the frequencies going up correctly, and down too when I `killall yes`