[RESOLVED] Kubuntu 24.04 doesn't sleep on Dell Inspiron 15 3530

[MartinDT]

My Dell laptop doesn't go to sleep, just stays on black screen with mouse cursor visible
Is it a problem with Intel Iris XE graphics?
As far as I know, this laptop is certified for 22.04 version.

Operating System: Kubuntu 24.04
KDE Plasma Version: 5.27.11
KDE Frameworks Version: 5.115.0
Qt Version: 5.15.13
Kernel Version: 6.8.0-35-generic (64-bit)
Graphics Platform: X11
Processors: 12 × 13th Gen Intel® Core™ i5-1335U
Memory: 15,3 GiB of RAM
Graphics Processor: Mesa Intel® Graphics
Manufacturer: Dell Inc.
Product Name: Inspiron 15 3530

[MartinDT]

hmm... looks like my problem has been solved.
just to add complete information... initial Kubuntu 24.04 comes with 6.8.0-31-generic kernel and after update to 6.8.0.35, I wasn't able to boot to KDE login screen.
I had to press ESC to get to grub menu and choose recovery mode and then resume, which led to KDE login screen.
I found useful info on this forum how to resolve this boot issue:
https://www.kubuntuforums.net/forum/...er-first-start
Removing quiet splash - post from Dido1.

Since then, I am able to boot to KDE login screen without going grub - > recovery mode and sleep works now too.
Today, I've also updated linux-firmware package, so I'm not completely sure about solution, but one of these two steps definitely helped.
Hope this helps to other users of DELL Inspiron with Intel graphics.