The timeline preview looks correct, but the final MP4 contains a few bright green frames around transitions. Changing export settings moves or removes them. What should I test before rebuilding the project?
Start with a short software-encoded export. Green frames often point to a decode/encode/GPU path. If software output is clean, update the GPU driver and retest hardware acceleration.
Clear render/preview cache and regenerate the affected section. A corrupt cached frame can survive project edits and keep reappearing in exports.
If the issue follows one specific source clip, transcode only that clip to a stable intermediate as a diagnostic. Converting the whole project would hide useful evidence.
Software encoding removes the green frames in my test. I will clear cache and update the driver before trying the hardware path again.