Ubuntu only starts with black screen on current kernel version (5.11.0-25-generic)

I am using Ubuntu 20.04 on my HP Elitebook G5, but I have got the problem that it only shows a black screen after startup (after showing the GRUB Manager). When I connect an external display to the laptop, it is working like normal but the internal screen still does not show any image. If I boot the laptop with an older Kernel Version (i.e. 5.8.0-55-generic) then the internal screen is working again.

Could this be related to a driver issue?

Many thanks for your help!

I'll provide this work around that I gave in comments; but it doesn't resolve the issue and keep the HWE kernel stack.

Ubuntu LTS releases have two kernel stack choices:

• GA (general) , or
• HWE (hardware enablement).

One option you have is to revert to the GA kernel stack (ie. assuming you're on 20.04 LTS; you didn't say). The GA stack uses the 5.4 kernel which is supported the entire life of the product.

You can have both GA & HWE stack installed; giving you an option when newer HWE kernels give issues; meaning you can now and again try the HWE stack and in time the issue will hopefully be resolved :)

For details on stacks & reverting from HWE to GA, please see (search for "To downgrade from HWE/OEM to GA kernel:"

https://wiki.ubuntu.com/Kernel/LTSEnablementStack

There are NO security risks with the GA kernel; all security patches are updated to it (and it's secure given it's patched, unlike using the now unsupported 5.8 kernel you were using. The GA (5.4) kernel is the default for servers, as it's seen as the stable choice; the HWE is for desktops which may need newer kernels for new video graphic stacks.