Does anyone know how to fix this issue: most of my clips are coming out completely shaky in timeline as well as export.
I've tried everything I know at this point and nothing worked.
Provide a sample of 'shaky' clip, please. Detailed info about source file, timeline and effects also may help.
i uploaded a sample here: https://youtu.be/eq1NfuM4ygI
video is of two clips both are 29.97 fps 1920x1080p on import, in timeline and export. you'll see the shaking in the second clip halfway through
Seems the source is an iPhone/Smartphone recording. So the most likely cause of the issue is VFR (variable framerate). Convert your files into CFR (constant framerate), that should fix the issue. You can use Handbrake tool for this. How To Convert A File To A Perfect MP4 In Handbrake - YouTube
Is the original media shaky?
no not at all. none of the clips are shaky