Timeline is jittering after this update.

Take a look at this FAQ on deleting the media cache after updating Premiere Pro: FAQ: After updating Premiere Pro, should you delete media cache?

If that doesn't resolve the jittering, let us know more about your media, your Premiere Pro version, and your media specs. See this FAQ for guidance on what to include: FAQ: What information should I provide when asking a question on this forum.

Saying you've tried every solution possible doesn't give us much to go on. Let us know exactly what you've already tried, that will help narrow down the possibilities.

If you’re using a keyboard shortcut to play can you please try the play button on the screen to see if it works better. (Trying to trouble shoot here.)