My Steam Deck’s cooling fan isn’t working properly.

Hi guys,
Here I want to share my experience with my Steam Deck. I've had my Steam Deck for about 2 years now, and it's the LCD version. As the title says, my Steam Deck has a problem with the internal cooling fan that doesn’t run properly. Specifically, the fan only runs at around 400–1000 RPM when the temperature is around 40–55°C, but it stays the same even when the temperature reaches 60–70°C. Normally, I’m sure it should be around 2000–3000 RPM.

When I'm playing AAA games and the temperature reaches 70–80°C, the fan still stays at the same RPM, so sometimes it gets overheated and causes frame drops. Then suddenly the fan jumps to around 7000 RPM and goes back down again to 400–1000 RPM. Sometimes the fan works normally for a while and run at 3000-4000 RPM.

normally in the far cry 5 it would be run the fan around 5000-6000 RPM. But it didn’t work, and I’m still getting really bad frame drops to 15 FPS. and suddenly back to normal in second video and the temperature reaching up to around 70-80°C.
the AAA games mostly like this in the first time i run the game, after several times it would be normal and get 60 FPS but sometime back to not normal again, but the worst one is when playing not AAA games, when the temperature is not high.

Does anyone else have the same problem?, I’ve already tried tweaking the fan settings, but it didn’t fix the issue.
I really need help to fix this issue.