I've had two issues, with two Elitebooks, one 845g8 (amd) and one 840g8 (intel). These are ~2020 models IIRC, which I had at the end of 2020 for the amd and early 2021 for the intel.
They both shipped with Windows 10, which I didn't use for any length of time, since I daily drive Linux. I updated them both to the latest Windows 11 available at the time, with a fresh install, and installed all the drivers from HP.
With the AMD, fresh out of the box, there was some issue with the backlight. The screen would be very dim, even while set all the way up. I initially thought there was some hardware issue, but booting into the BIOS burned my eyes, so the hardware was fine. I didn't really use it for any length, so don't know how that install fared otherwise. After the reinstall, the backlight worked as expected. But, for around half a year, the webcam wouldn't be detected. It suddenly started working after some update or other. This machine can also not sleep for any length of time under Windows. It will usually reboot by itself after a while, and Windows has no idea why (event log says "unexpected shutdown"). Less often, though, it will just get stuck when attempting to wake up (fans full tilt, screen off). The hardware was otherwise in good working condition, since everything worked under Linux since day 1. Yes, including sleep and audio.
With the Intel, the backlight seemed fine initially. I also didn't spend much time with it as delivered and reinstalled it. First off, Windows didn't detect the touchpad, nor the trackpoint, nor the Wifi. I did have a mouse lying around which worked (fortunately I don't care for BT peripherals), but then would have had to jump through some hoops to convince it to not insist on connecting to some server. Fortunately, it was going to be domain-joined so it left me be. Then the fun started. With the HP usb-c dock, the external screen would usually not be recognized at 4k@60 unless I did a plug-unplug-replug at the right time. Sleep would also be unreliable, sometimes waking up to a blank screen and fans going full tilt, sometimes to a garbled image. The output thing has been fixed after a while by using the drivers from Intel's website, but Windows would helpfully update them every other day to the borked ones. In the end, the drivers supplied by Windows have caught up, but my other random Chinese dock still won't output 4k@60. Sleep also mostly works fine now. Never had any issue on Linux. The Chinese dock works fine on Linux, and also on Windows with the AMD laptop.
