If I select a kernel from the list, press the Set boot button, and reboot, the desired kernel becomes the default kernel to boot. However, the check mark in the Default column in the interface does not move to that kernel. I do not recall seeing the typical Apply changes box appear as expected after pressing the Set boot button.
If I change the Set boot kernel again to another kernel, no Apply change box appears, but the kernel that is booted is correct and matches the choice made. Again, the check mark in the Default column does not move to the selected boot kernel.
It's purely cosmetic as the selected kernel always seems to be the the kernel that boots.