Made another video with CPU load overlay, I know CPU frequency even if max is not same as CPU load but here you can see that rotate the screen set the prime core to max clock (not load) so the core is not properly used for whatever reason. https://www.youtube.com/watch?v=321sGbX6MKc
Edit: tested another overlay app where I can set the refresh rate https://www.youtube.com/watch?v=rWxsMizcTZc