Just to avoid a misunderstanding. This is nothing a DietPi update will fix as it is an issue of the Armbian kernel for your board.
Did you tried to downgrade the kernel and mark them as on hold to avoid further updates?
apt install linux-dtb-current-rockchip64=21.08.2 linux-image-current-rockchip64=21.08.2
apt-mark hold linux-dtb-current-rockchip64 linux-image-current-rockchip64