Perhaps combining the proxy feature with preview scaling will improve preview performance.
Either way, W10 sometimes has background processes (updates and other services) that can have an influence.
You can try restarting Shotcut after changing that. Also, you can try changing Settings > Display Method. If neither of these help, then I do not know what is wrong, and more logs or a screen recording will not help.
EDIT: Could it possibly be a PC problem?? All the different display methods don’t work sadly, lol
EDIT 2: Also when i watch the whole thing it doesn’t lag, but if i skip forward it lags… Is this a PC problem lol, i am very noob.
EDIT 3: Yes, i lowered the fps and quality of the video, and it worked. I am going to open my PC later in the future and see what the problem is. Thanks so much, and being super kind to me :>
EDIT 4: I just put it back to HD and 60 fps and it still works amazinly, i am super confused lol. Thanks tho :>
EDIT 5: ok ill stop after this, but if its lagging anyone just change your video mode to like anything, and it literally works like magic.