After Effects rendering problem

I use After Effects 2021, my pc is good.
The problem is that recently the rendering of videos on my PC takes extremely long, which was not so until recently. I render my videos with Adobe Media Encoder.

The problem exists only since I recently reset my preferences. When I held down ctrl alt and shift while launching after effects, I got a message that my presets were reset and then another error message that I can't remember what the error was (if it's related to the rendering problem I don't know).

I also don't know if it's normal that the graphics card is only loaded up to 6% when rendering (I'm rendering with GPU acceleration).

Anyway, now I need 1 hour render time for a 18s video. I have a lot of effects on the clips but earlier it took only max. 2-10 min. with my PC.

It annoys me that I can not render projects fast...
Until recently, there was also sometimes an error where the complete render voorgang has stopped because media encoder has rendered too long on a frame. Now media encoder renders every frame very long (it takes forever).

My after effects also doesn't load the cached frames properly I think, because sometimes the area that is green in the timeline doesn't get bigger anymore and it repeats the green area. Also sometimes the green areas just disappear or turn blue.... very strange (again i don't know if it's related to the render problem).

Upgrading the software (AE and AME) does nothing. I have also tried many other ways to solve the problem, but nothing has worked.

If i should upload any screenshots tell me.