CoreTemp isn't the most reliable monitoring program, it doesn't work completely accurate with all CPU. It might be that short workloads may stress the CPU and for that short peroid of time the fans ramp up to adjust to the load, which CoreTemp probably can't log fast or accurate enough. Also since you mentioned that CPU temperatures exceed 90°C, the TIM probably has turned worse sooner than expected and a re-paste, ideally of both CPU and GPU will help with general temperatures and prevent temperature spikes, thus enabling the fans to spin at a lower RPM throughout all workloads. I personally recommend using Thermal Grizzly Kryonaut, as it's simply the best thermal paste (not including liquid metal for obvious reasons) on the market since it's debut. Medion notebook are quite user-friendly to maintain (at least in my experience), so the process should be faily easy if done carefully. EDIT: Are you using the latest 2.12 BIOS version? If not, I recommend updating it. It's worth upgrading it alone for the CPU microcode updates and although the changelog doesn't specifically state it, a newer BIOS version might include a tweaked fan profile. Here's the link to that BIOS. I would still recommend re-pasting as this will help with both CPU and GPU temperatures significantly.
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