Alas this "Workaround" didn't help. I've since tried Ubuntu Unity 22.04 with Kernel 6.2.0-33-generic and Ubuntu vanilla aka GNOME with the same kernel on 22.04.1 and the screen dimming when I move the pointer around the screen and then goes brighter within a second of none movement, the issue is also there when typing either in the terminal window or the the search on each menu hud, and on anything else that shows a text box, type and it dims then stop and it goes brighter.
To me, it seems r either the MESA driver for the older Intel HD GPU's has reached its EOL or something for changed in the later Kernel's 5.19 and 6+ has broken and either no one has noticed or those like myself are just running 5.15 and a version/flavour of 20.04LTS or 22.04LTS with the aforementioned Kernel.
I'm not too fussed about putting 20.04LTS back onto the HP Elitebook 8440p as I use Ubuntu Pro to keep the security patches etc going till 2030.
It's sadly put me off updating my 2 Plex servers to 22.04LTS for the time being, even though one of the machines run the Nvidia Quadro GPU, but the second server uses the Intel GPU on the i3 3240.
Is there any way I can report this issue to the Kernel Dev's just to highlight the issue? Or any of the Ubuntu flavour Dev's so it can be looked at?
Cheers for the help!
Dave