latest kernel has gone from 4.19.8-x86-... to 4.18.16-x86_64-...

The 4.19.8 kernel has been found to report the wrong uptime number.

Run the "uptime" command and see what it says. :-)

I haven't heard of any other issues.

We rolled back our latest kernel to 4.18.16 due to an issue with inaccurate uptime outputs in 4.19 kernels and up. You can find some discussion on this issue here and here. Our 4.19 kernels are still available for use in your Linode's configuration profile (Settings > Advanced Configuration).

Thank you very much! :)