When installing the linux-lowlatency package on 18.04 LTS, the lowlatency-kernel version 4.15 is installed, while the -generic kernel has been updated to 4.18 since the LTS release.
4.18 linux-lowlatency packages are only available for cosmic and later releases.
Is there any way to automatically get new lowlatency-kernel versions on 18.04?
You need to install
linux-lowlatency-hwe-18.04
, aslinux-lowlatency
will always install the original version, 4.15, in this case.