I think this is related: Long-term load on Pi-Hole Instance - Help - Pi-hole Userspace
See also the linked thread in Armbian forum about high CPU temperature/usage on other boards with this kernel family.
EDIT: Here a new kernel package with Linux 6.6.29:
cd /tmp
wget https://dietpi.com/downloads/binaries/testing/linux-{image,dtb}-current-sunxi.deb
dpkg -i linux-{image,dtb}-current-sunxi.deb
rm linux-{image,dtb}-current-sunxi.deb
reboot