"mysterious" change after recent update

I observe a "mysterious" change after the recent update.
My video card, EVGA GeForce GTX 1070 TI typically runs cool around 24 to 27°C with the fans only idling inaudible.
When playing games or using apps that use the GPU i.e. video conversion apps, depending on the load, the fans sometimes start to spin up to higher RPM as the core heats up. all of course depending on GPU load. Typically for the time of the active process. Thereafter the go back to idle.

Since the last Windows 10 cumulative update about a week or 2 ago however, there is a "behavioral change" in my system.
Now from time to time even on slightly increased CPU loads, the video GPU fans start revving up and then after a short while waning.
Now this suddenly happens with any app whether they can use the GPU were not.
If I play a [streaming] video or watch YouTube clips, if my backup runs or any other task that increases the CPU load, now the GPU fans start to kick in.
Everything is clean, there's no dust buildup either.

This was not the case before the last cumulative Windows 10 update.
Anyone know something about this?