I did put out a question a few days ago about this issue, but I seem to have hit a brickwall!
My Laptop is the HP Elitebook 8440p Intel® Core™ i5 CPU M 540 @ 2.53GHz. The issue I have is when I uupgrade to either Kernel 5.19 or the latest HWE kernel, where when I move the mouse either with the Touchpad or a USB mouse the screen goes dim, but a few seconds after I stop moving the pointer the screen goes bright, and also when typing the same happens, as when I stop the screen goes bright again.
I've since reinstalled 22.04LTS but have kept the Kernel version 5.15 on for the time being. Can anyone tell me what this issue is caused by? is it a MESA driver issue or a Kernel issue? I'm tearing what hair I have left on my head out trying to work this out.
The BIOS has no powersaving selectable, so it's not the same issue as the Dell Laptops had from a few years ago.
Many thanks in advance for any input, if all else fails I may report it as a Bug on the Kernel pages and see if someone there knows.
Update - Just after I made this thread the screen went black with a blinking cursor and wouldn't let me get to the Terminal, yet this is using 5.15 on 22.04LTS, I know if I revert back to 20.04.6LTS I have no issues whatsoever. I'm considering either downgrading to 20.04LTS or switching to another flavour of Ubuntu, something I don't really want to do.