Slow Playback

So I know that its not due to the power of my PC because I use another PC at work which is weaker than my private PC but I dont have this Issue at work. Interesting is that it doesnt even matter if I change the proxy resolution to half or quarter. The playback has exactly the same choppy playback framerate. Please someone help me. I searched so long but couldn't find a solution that works for me yet.
Yes I have the newest version of Davinci. (Studio version)
Yes my graphic drivers are up to date.
The CPU and GPU usage are somehow always under 30% usage in Davinci so why doesnt it use the power?
Specs:
Ryzen 7 2700x @4GHz
GTX 1080
16GB DDR4 3200MHz
Asus Strix B450 f-gaming Mainboard
Win 10
3 Monitors - 2 in FHD 60hz, 1 in WQHD 144hz
The Project and Timeline resolution is 1920x1080 and 30fps. The footage is also 1920x1080 but in 60fps and just a simple mp4.
Yes I have the newest version of Davinci. (Studio version)
Yes my graphic drivers are up to date.
The CPU and GPU usage are somehow always under 30% usage in Davinci so why doesnt it use the power?
Specs:
Ryzen 7 2700x @4GHz
GTX 1080
16GB DDR4 3200MHz
Asus Strix B450 f-gaming Mainboard
Win 10
3 Monitors - 2 in FHD 60hz, 1 in WQHD 144hz
The Project and Timeline resolution is 1920x1080 and 30fps. The footage is also 1920x1080 but in 60fps and just a simple mp4.