Sorry for the inconvenience caused. Could you please help check the following:
Are the multimedia source materials videos, image sequences, or animated textures?
Does the issue happen in all projects, or only in this specific scene?
Approximately how long is the video, and how many shots or clips are in the timeline?
If possible, it would also help a lot if you could share a screen recording of your workflow showing the issue. Thanks and I look forward to your response.