I recently reinstalled Neon (after new ISO) having not ran KDE for six months or so (I'm very happy btw with the current version).
I noticed kernel was still a 4.18 and updated to a 5.0, and then forgot about it. After I rebooted and switched to the 5.0, my resolution shot to 1024x768, and the issue seemed to be that my monitor wasn't being detected correctly anymore.
I fell back to the packaged kernel, and all was well.
For my edification, can anyone explain the why to me?

Seems I always end up answering my own posts. Is that because the forums are dead or my questions are too hard (or too stupid for some)?

Anyway, in the spirit of documentation and edification, apparently the issue is that one must install the HWE components of the kernel as well. The HardWare Enablement seems to be an Ubuntu thing.

To answer your second question about not getting a response in a short amount of time, it depends on which sub-forum you post in as some are more active than others. Posting this over in the KDE Neon sub-forum, which is very active, may have gotten you a more timely response (of course with your having edited your first post without including a timestamp for the edit, we can't just look and see how much time passed between your originally posting and when you came back and edited in your answer; so there's no telling if even in a more active forum there would have been enough time for someone to respond).

Well Airdrik, I do appreciate any response. It's just that I felt this (since about kernels) was specifically a linux question so I put it where it seemed appropriate (being a good netizen).