I took an update from 22.214.171.124 to 126.96.36.199. My machine would not boot from the new kernel. I tried removing the latest kernel using: sudo apt-get purge linux-image-188.8.131.52-generic and sudo apt-get purge linux-headers-184.108.40.206-generic. It successfully remove the kernel files and "update-grub2" show two remaining kernels (220.127.116.11 and 18.104.22.168).
When I reboot the machine continues to try and boot 4.15.34. How do I really kill it? In my messing around I can only successfully boot 22.214.171.124 now. How do I get things back to normal?