Glitching at the start of clips since update v14.0

Is this footage from an iPhone?

Thanks,
Kevin

Similar issues here.  Anytime I do a time remapping on a clip, it stutters and won't play back right.  On multiple clean systems.  Something with the 2020 update - possibly the code they changed to allow more than 1000% time remapping without nesting is my guess.  This one is a huge issue for me.  I use all 23.976 sequences, and all footage (prores 422 .mov files) are interpreted to 23.976 before i ever put them on my timeline.  As soon as I try to do any time remapping it skips frames and won't play back correctly so I have no way of seeing my speed ramps unless I take the time to export every time i make a change to see it.  Driving me insane.  I would have thought they would have fixed this by now - saw a photoshop fix already addressing some issues.  This one seems to be affecting a ton of people from what i've seen and heard in other groups i'm in.  I also tried it with some other .mp4 files from a sony and same issue.  Doesn't matter what footage i use - in case adobe support sees this.

Hi Merlijn,

Can we have full system info and the media type you are working with? Are these speed affected clips?

Thanks,
Kevin

Looks like this might be an issue: https://community.adobe.com/t5/Premiere-Pro/Speeding-Up-Footage-Results-in-Lost-Frames/td-p/10729596