HP ZBook Firefly 14 G11 (Ultra 7 155H / RTX A500) - Fan gets stuck at high RPM

Hello everyone,
I’m a complete Linux newbie and to be completely honest, I have no idea what I’m doing yet! I’m running Fedora KDE Plasma on a new HP ZBook Firefly 14 G11.

I have an issue where the fan spins up under load, but refuses to spin back down after everything has cooled off. My temperatures are totally fine (CPU is around 38°C - 43°C), but the fan stays loud forever. The only workaround is putting the laptop to sleep and waking it up again – then the fan stops and behaves normally until the next heat spike.

What I’ve checked/tried so far:

  • BIOS is updated and “Fan Always on while on AC Power” is disabled.
  • Booting into an older kernel didn’t change anything.
  • I already have the proprietary NVIDIA drivers installed. The RTX A500 runs perfectly fine and properly goes to sleep when not in use, so I have already tested and ruled that out.
  • With the help of the Gemini AI, I tried installing thermald and also tried to override the fan control with nbfc-linux. To be honest, I don’t really know what exactly I did there, but it didn’t work anyway (the laptop hardware completely ignored the NBFC commands). I have since uninstalled those tools again.

Does anyone have an idea how to fix this or has experienced the same with recent HP ECs? Thanks in advance!