The newest kernel, 220.127.116.11-pclos1.a64, should now be the default one. I'm wondering, did you get a little impatient when installing it in Synaptic? It takes some time to finish the whole operation, because part of the process involves building an initrd file for the kernel. I would suggest you open Synaptic and mark the 18.104.22.168-pclos1.a64 kernel for reinstallation. It may appear that Synaptic is doing nothing for a minute or two, but don't interrupt it.