I don't understand what's going on with my laptop?

So I have had my laptop for 2 years and now for 2 - 3 months it totally annoys me.
For example, when watching YouTube, Twitch or something else (also in games) the Intel jumps to 100% and the sound sounds completely strange, incomprehensible and e.g. The video is like slow motion as long as the Intel is at 100%. Why is that? With games like Fortnite, Minecraft or something like that, it sometimes happens then I only have 10 FPS or something and it feels like slow motion and the sound becomes strange.

Specs: Intel I7 7700 HQ CPU 2.8 GHz

Nvidia GTX 1050 TI and an Intel HD Graphics 630

24 GB Ram, 256 GB SSD, 1 TB HDD

I have screenshoted this briefly at Twitch

Have you cleaned your laptop once in 3 years? If not, it's probably because. If the fan of your CPU is completely clogged, it can't get rid of the heat and therefore the performance drops.

Okay could be an idea, actually I use such an extra cooler but it broke.

Uninstall both graphics drivers and then reinstall them. (First install the Intel)

If that doesn't help: what are the temperatures like?

How could I best see it? (with the temperatures)
And uninstall the graphics driver, so should I now uninstall the device in the device manager?

Try defragmenting your disk on the Windows (or both I assume Windows is on the SSD) that works if you simply enter "defrag" in the search option in the taskbar, then it "sorts" again in principle that it is for things does not take that long (theoretically not absolutely necessary with the SSD but you can still try it.)

Otherwise it will probably run better if you set it up again if you want to do that, all files that you downloaded yourself are gone etc. So it only installs the operating system and all the data that it had from the beginning

No, via the Control Panel → Uninstall a program.

Thanks, I'll do that with the Defrag.
I've already done that with the new one

Oh okay, because so far I've only tried to make out the Intel graphics card, but have noticed that it is connected to the monitor and that does nothing. Or makes worse.

Does the problem only occur with the battery, only with the mains or both?

So far only in mains operation, because the laptop is a bit slower in the battery and I don't think it gets to the point where it is so busy.

What happens if you say in the nVidia settings area that you only want to use the "high-performance graphics card" and not "as required" the iGPU? So you would also avoid "load-dependent switching"…

I already did, I also went into graphics settings and set that there too

Okay ^^