You don't give us very much to go on, and it would be great if you'd follow the steps in the Read Me Before Posting stucky thread and attach the DxDiag results. It would also help if you made a screen recording showing exactly what the problem looks like, as sometimes that will contain significant clues.
You might also consider packing the project and uploading it to a cloud folder and pastng the link here so other people can test your exact project. Obviously, don't do that if you're not comnfortable sharing those source clips, but the more specifics you can provide, the better the chances are that other forum members can help.
YouTube/optodata
DS365 | Win11 Pro | Ryzen 9 3950X | RTX 4070 Ti | 32GB RAM | 10TB SSDs | 5K+4K HDR monitors
Canon Vixia GX10 (4K 60p) | HF G30 (HD 60p) | Yi Action+ 4K | 360Fly 4K 360°