Kling O1 Upload Error

I'm trying to upload a video clip to be modified by O1 but Kling keeps saying it detected an error in the clip. I've tried both mp4 and mov wrappers but I'm wondering if it could be a color space error? It's a clip I exported from DaVinci Resolve and other types of mp4 clips work just fine. I can't seem to find any spec sheet released by Kling that details format requirements. Any hints out there?