The kernel must find matching installed modules:

echo "Running kernel: $(uname -r)"

echo "Newest installed modules: $(ls -v /lib/modules | tail -n 1)"

ls -la /lib/modules will show what modules are supported by the various kernel versions

ls -l /boot/firmware/kernel*.img will show the kernels there will be kernel8.img or for Raspberry 5 kernel_2712.img but this will not show the kernel versions

dpkg -l | grep -E "raspberrypi-kernel|linux-image" will show the available kernels. The newest kernel or what them meta kernel package points to apt-cache depends linux-image-rpi-v8 will be taken. A safety mechanism will not purge an old running kernel.

sudo reboot after the update will start the new kernel started.