Hi Echo_Lake,
Thank you for your reply.
I'm a little bit surprised to hear that the ventilation should be a problem since the device was just inspected by an HP authorized service and the laptop is half a year in my possession. Just to assure you the laptop has clean vents, cleanly installed Windows 10 and all the HP updates together with the BIOS updates that probably started my problems.
After doing some additional search and putting in more of my time than I should I have found out that from the BIOS version F28 (currently F40 running) you have modified how the laptop is handling the power delivery as well as fan speed. I have no option to increase the fan speed in Windows unless I enable the Comfort mode in HP Command Center which locks my CPU clock to a slower speed but the fans actually run which seems nice.
I have tried and installed ubuntu where the problem is not so obvious, so I assume some people are correct that you have some kind of code that is Windows-specific and ensures that the laptop fans are not running. From the current knowledge unless HP does a BIOS update that will bring me back to F28 state or at least allow me to downgrade the BIOS I won't have any better results. It's hard to prevent myself to not open the PC and just re-paste the GPU and CPU with a good thermal paste to check if there is any difference but I don't want to lose my warranty since I have seen some pretty strange things in my half-year use.
Hopefully, HP didn't make the same mistakes with the new Spectre 15 (2020) version but I noticed that you have made bigger holes for cooling and I think you are to concerned with the fan noise. I have bought an ultrabook with a 45W CPU and if I want to use it I'm aware that there is a lot of heat being produced from it and the cooling is capable of keeping the device cool if it would run.
Side note: I have noticed that if I run a stress test in the UEFI firmware the CPU reaches only 80 degrees max while in Windows 10 with any benchmark the device reaches 95+ degrees in 10 second. You should take a look at it or be aware that some users will notice that a stress test isn't so stressing the CPU as it should.